This is probably a topic that's been on a lot of people's minds, including mine, and I was curious how people would expect their ideal fight between these two go. Because, Jiren is strong, and we all know that. However, Hit has Time Skip which... in itself is extremely powerful, mostly due in part because Hit is strong in himself, but getting attacked during a Time Skip is the equivalent to being hit without being able to brace yourself for it. It's like getting sucker-punched, which is what makes it so strong. No matter how strong someone is, if you get hit in a vital spot without seeing it coming, you're gonna take heavy damage, as shown in the Champa Arc. Most traded blows in Dragon Ball are normally anticipated and when they hit, you've most likely already braced yourself for it, and can absorb most of the initial damage, but with Time Skip that is completely bypassed, unless you're Goku and can predict the attack ahead of time. Which, this is a technique that I'm not sure Jiren is initially aware of, and that's what can make or break a fight between the two is if he's aware of that ability.
Also, are we going to rule out Hit's dimensional powers as well? Unless his pocket-dimension is still destroyed, no thanks to Goku. But, this isn't a topic to say why the fight would be in Hit's favor, but more or less to discuss how you would interpret an ideal "fight" and not a one-sided, Time Skip spam-fest. Because, we all know Hit enjoys a proper martial arts duel, as shown when Goku and Hit had their rematch. Also we all know, in our heads, there will be some sort of caveat to the fight that would make Hit actually struggle.
To be quite frank, IF they ever decided to have the two go at it I'd imagine the fight would go on for some time, and then Goku steps in and interrupts the fight to let Hit get away or something. I dunno. I'm bad at expectations, when I haven't exactly had time to think about, and would much rather hear what you all would have to say
