Why was Merged Zamasu losing his immortality?

[Freeza9000]

Personally, I don't really buy the whole Merged Zamasu losing his immortality because of a mortal body clashing with it. If that was the case, then why wasn't Future Zamasu's immortality clashing with his mortality? I mean, Future Zamasu was once mortal and has to wish for his immortality. I know one person will say that the writers wrote themselves into a corner by having an immortal antagonist that would be literally impossible to beat and the immortality had to be nerfed due to plot convenience, but they had the Mafuba which they could use to seal Zamasu.

[Boo Machine]

You don't really have to buy it I guess, but it is what they told us. That it was the mortal half that was weakening the immortality. So I'm not sure what you're looking for. I mean if I'm pretty honest I kind of like the idea that Zamasu screwed himself out of his own immortality. It would have been a cool way to end it with his death if it didn't turn out that his soul still lives on to devour worlds.

I would have much rather had the Mafuba as well but, oh well.

[Doctor.]

50% of his body was mortal.

When future Zamasu wished for immortality, 100% of his body turned immortal.

Not sure what's hard to get here.

[Freeza9000]

You don't really have to buy it I guess, but it is what they told us. That it was the mortal half that was weakening the immortality. So I'm not sure what you're looking for. I mean if I'm pretty honest I kind of like the idea that Zamasu screwed himself out of his own immortality. It would have been a cool way to end it with his death if it didn't turn out that his soul still lives on to devour worlds.

I would have much rather had the Mafuba as well but, oh well.

I do somewhat relish the idea of Zamasu's other self (whom he shows more care and consideration more than other beings is literally himself lol) screwing him over and making him lose immortality, but I just don't buy the logic and reasoning behind it. If Merged Zamasu was losing his immortality due to fusing with a mortal body, why wasn't Future Zamasu's immortality clashing with his mortality? Keep in mind that Future Zamasu was once mortal.

50% of his body was mortal.

When future Zamasu wished for immortality, 100% of his body turned immortal.

Not sure what's hard to get here.

If that was the case, then Vegetto would have to be half dead when he fought against Super Boo since Vegeta was dead if I recall (my memory of the Boo Arc is a bit foggy so forgive me. Haven't watched/read that in a long ass time).

[Boo Machine]

You don't really have to buy it I guess, but it is what they told us. That it was the mortal half that was weakening the immortality. So I'm not sure what you're looking for. I mean if I'm pretty honest I kind of like the idea that Zamasu screwed himself out of his own immortality. It would have been a cool way to end it with his death if it didn't turn out that his soul still lives on to devour worlds.

I would have much rather had the Mafuba as well but, oh well.

I do somewhat relish the idea of Zamasu's other self (whom he shows more care and consideration more than other beings is literally himself lol) screwing him over and making him lose immortality, but I just don't buy the logic and reasoning behind it. If Merged Zamasu was losing his immortality due to fusing with a mortal body, why wasn't Future Zamasu's immortality clashing with his mortality? Keep in mind that Future Zamasu was once mortal.

I think the logic works well enough. There isn't really explanation for why it didn't work the other way. It just kinda doesn't. I guess if you want a random head canon, then maybe immortality can't be passed to someone else because the dragon only gave it to one person and one person only and sharing it with another would be cheating the Dragon Magic?

[Jinzoningen MULE]

Here's my crazy, unfounded hypothesis. If Future Zamasu had been born immortal for some reason, Merged Zamasu would have been immortal, the same way that Merged Zamasu was SSR despite not having a purely Saiyan body. However, Zamasu's immortality wasn't an inherent characteristic of his body, it was an external trait given to him by Dragon Balls. That being the case, the magic didn't "know" (for lack of a better word) to envelop the entire non-Future Zamasu body. Once Merged Zamasu became severely damaged, it became noticeable from his appearance that only half of his Cells were able to revive.

[Merged Zamasu]

Future Zamasu was 100% immortal. There was a balance between Future Zamasu's immortal soul and Future Zamasu's immortal body, as such he was able to regenerate in an instant after Goku shot him in the face. Merged Zamasu was only 50% immortal. There was instability between Zamasu's immortal soul and Zamasu's half mortal/half immortal body. Black's half of Zamasu was made up of the same purple juice that we saw when Goku briefly disintegrated Future Zamasu's face. But unlike Future Zamasu, that half was not immortal, as Black wasn't, and so the purple juice didn't go away. Merged Zamasu wasn't losing his immortality. He was born flawed, the two fusèes clashed with each other inside a single body, as a result Merged Zamasu was unstable. Yet, there really wasn't any other choice. Black possessed powers that surpassed even the likes of Goku and Vegeta, but he was mortal, fragile. Future Zamasu had the supreme strenght and comfort of immortality, but he was weaker than Goku and Vegeta. Only through fusing they had a chance to win, there was no other way.

I'll agree it wasn't very well explained. What do you expect? Merged Zamasu appeared in 2 episodes and a half (Bodiless Zamasu of Episode 67 was still Merged Zamasu), you expect them to go into the details?

[Lord Beerus]

50% of his body was mortal.

When future Zamasu wished for immortality, 100% of his body turned immortal.

Not sure what's hard to get here.

If that was the case, then Vegetto would have to be half dead when he fought against Super Boo since Vegeta was dead if I recall (my memory of the Boo Arc is a bit foggy so forgive me. Haven't watched/read that in a long ass time).

But Vegetto being half dead ultimately doesn't matter because Vegeta retained his body after death. It's not like Goku fused with a literal spirit. He fused with a being that, while he was technically deceased, he had a physically body that was capable of doing anything that a being in the living mortal realm could do.

[Mazingerdestro]

The potara seem to be capable of merging anything of the same nature. For example mortal+mortal, deity+deity etc.
In black+Zamasu=Blamasu, 2 person with a different body+nature combined.

My idea is that the fusion was failing:
1) Black's body was human and zamasu's godly. A godly being can achieve a perfect no time limit Fusion while a human has only 1 hour. Merged Zamasu was struggling to keep the fusion beyond the one hour time limit that resulted in his body slowly dying.

2) Immortality in db equals 100% regeneration. The 50% of Merged Zamasu that was mortal was sustaining serious damage that it couldn't 100% regenerate due to lacking the regeneration ability initially.

3) Both 1+2 contribute

[GodKaio-Ken]

The half that was Black did not become immortal by merging. Potara Fusion obviously does not have the same power as the Super Dragon Balls.

Also his soul never stopped being immortal...only the body so there is no contradiction. You dont have to buy it but the body of Black more or less corrupted the immortal body of Zamasu.

[MondoCool]

The way I have always looked at it is Zamasu was immortal, in this sense, he was pure/perfect. When he fused with Black it diluted his perfection. Kind of like if you took a soda in a glass then replaced 50% of it with water.

[Lord Frieza]

I dont think its just the mortal body + immortal body thats the problem.

Everything about this fusion is wrong, the fusees have significantly different power levels and Black was a SSR when he fused so he cannot power down which puts a tone of strain on the Fused Zamasu. Couple that with the conflict of the mortal body + immortal body and you can see why he body went so...wrong. His immortality is trying to cope with battle damage, an unstable body, fluctuating energy and super zenkai enforced power increases from pain. Its no wonder his body mutated and deformed with all that going on inside him. All that combined with the clash of mortal body and immortal body and it pushed the immortal flesh to its limit and beyond, it was the only thing holding his unstable body together.

I also think thats why he started to have trouble with Goku, Vegeta and Trunks, his power started fluctuating beyond his control and he could not summon the energy to push back their attacks.

And technically he never lost it as his soul was still immortal, its just his body could not cope with everything I've just said.

[Jinzoningen MULE]

...the fusees have significantly different power levels

That was never said to be a problem with Potara fusion, but after first seeing this thread, I pondered a bit and came to the same overall conclusion as you. There are actually so many problems and potential problems with their fusion, something was bound to go wrong. Although I do think that Black's mortality had something to do with it, since it was so strongly alluded to.

[Lord Frieza]

...the fusees have significantly different power levels

That was never said to be a problem with Potara fusion, but after first seeing this thread, I pondered a bit and came to the same overall conclusion as you. There are actually so many problems and potential problems with their fusion, something was bound to go wrong. Although I do think that Black's mortality had something to do with it, since it was so strongly alluded to.

True but as you said its another potential problem stacked on top of so many others.

[Gog]

Because Goku Black... No really that was the actual reason Goku Black was the actual reason why merged Zamasu was falling apart.

[Merged Zamasu]

There wasn't any choice at all. Black had endless strenght, but he was not immortal. Vegito was inevitable, and Black would have been disintegrated by his FInal Kamehameha. Their own salvation was also a double edged sword. Besides, only the physical form of Merged Zamasu was flawed. Once he got rid of his body (Which Trunks didn't destroy, it self-destructed), his immortal soul was able to fuse with the Universe. So in the end, despite his flaws, Merged Zamasu easily overwhelmed Goku, Vegeta and Trunks, before finally meeting his demise at the hands of Zeno. But, before dying, he brought everyone down along with him, and now Trunks is forced to live the rest of his life with the burden that he did fail, and that those he swore to protect are erased from existence along with Merged Zamasu. This truly is justice.

Merged Zamasu's only weakness was Black's mortal half. And even then, if Goku, Vegeta and Trunks didn't have a power great enough to exploit that weakness, it wouldn't have been a problem. Black fused while in Super Sayan Rosè, but Merged Zamasu's immortal soul took care of it, so that it didn't harm Merged Zamasu's body.

[dragonballgeek]

Personally, I don't really buy the whole Merged Zamasu losing his immortality because of a mortal body clashing with it. If that was the case, then why wasn't Future Zamasu's immortality clashing with his mortality? I mean, Future Zamasu was once mortal and has to wish for his immortality. I know one person will say that the writers wrote themselves into a corner by having an immortal antagonist that would be literally impossible to beat and the immortality had to be nerfed due to plot convenience, but they had the Mafuba which they could use to seal Zamasu.

Half immortal. Half mortal.

While they destroyed his mortal body, his immortal spirit still remained. I think that's a fair ending.

[Freeza9000]

Personally, I don't really buy the whole Merged Zamasu losing his immortality because of a mortal body clashing with it. If that was the case, then why wasn't Future Zamasu's immortality clashing with his mortality? I mean, Future Zamasu was once mortal and has to wish for his immortality. I know one person will say that the writers wrote themselves into a corner by having an immortal antagonist that would be literally impossible to beat and the immortality had to be nerfed due to plot convenience, but they had the Mafuba which they could use to seal Zamasu.

Half immortal. Half mortal.

While they destroyed his mortal body, his immortal spirit still remained. I think that's a fair ending.

Which I question. How can one be half immortal? You either immortal or not.

[Merged Zamasu]

Personally, I don't really buy the whole Merged Zamasu losing his immortality because of a mortal body clashing with it. If that was the case, then why wasn't Future Zamasu's immortality clashing with his mortality? I mean, Future Zamasu was once mortal and has to wish for his immortality. I know one person will say that the writers wrote themselves into a corner by having an immortal antagonist that would be literally impossible to beat and the immortality had to be nerfed due to plot convenience, but they had the Mafuba which they could use to seal Zamasu.

Half immortal. Half mortal.

While they destroyed his mortal body, his immortal spirit still remained. I think that's a fair ending.

Which I question. How can one be half immortal? You either immortal or not.

Actually, Merged Zamasu was not half immortal. Merged Zamasu was 100% immortal. The only reason he was able to survive his self-destruction is because of his immortal soul. The proof of his immortality is his essence surviving despite the complete destruction of its physical host. His only weakness was the fact Black's half did not have regeneration at all, and so all damage was permanent. If you noticed, Merged Zamasu's purple juice is the same as the purple juice we briefly saw when Future Zamasu was blasted right in the face. So apparently, when you hurt Zamasu a lot, he doesn't lose limbs or anything, is skin just turns into creepy purple juice.

[Jinzoningen MULE]

Which I question. How can one be half immortal? You either immortal or not.

I guess he was still immortal at the end of the day, but his regeneration began to fail due to a mix of immortal and mortal cells. That's more of a language problem than a logic problem.