Zuno is potentially the most dangerous character in Dragonball history

[Perfectionist-Cell]

Just gonna but this out there for everyone.

Omniscient literally means you know everything, that includes the future. Whether he is truly omniscient or not is a whole different question. It is the same with Zamasu he is immortal but died from Zeno.

[R. Daneel Olivaw]

There was a theory a long time ago that there was originally one being that was so powerful that he split himself into three parts - Omnipotence (Zeno), Omniscience (Zuno), and Omnipresence (Zalama). He thought that the most powerful person should not also be the most knowledgeable and so weakened himself. This is similar to how the Nameless Namekian split himself into King Piccolo and Kami. Future Zeno wasn't even aware of what Zamasu was doing even though 12 Hakaishins and Kaishins were dead, with 12 Angels being inactive. In general as stated by Toriyama in an interview, Shenlon cannot grant a wish that exceeds the abilities of its creator. That would apply for Super Shenlon as well and if all universes were restored, then Zalama being omnipresent would have made sense.

Just a theory though.

Zuno by himself isn't all that great. If he was truly all knowing, he would have known Zamasu was going to come see him and prevent it or be ready for him.

I like to think that original being was Toriyama.