I think
@Midoriha and
@0takuDragonSlayer have said it best:
I bet you anything that over half of the people going "WOOOOOOOOOOOAH OHMA IS ALIVE SO HYPE" were the same people going "WOOOOOOOOOOOAH THE MC ACTUALLY DIED FROM THE TECHNIQUE THAT EATS AWAY HIS LIFESPAN SUCH GOOD WRITING".
No matter the explanation it comes with, this is genuine hack writing that completely undermines and trashes the whole point and message of Ashura.
The guy literally drops dead in front of Kazu. Its not even surprising that the writer brought him back (since this is a shounen)but frustrating he can't just focus o. one MC and let consequences stick. This essentially means all of that drama about him risking his life during the tournament was basically meaningless. All the risks of Advance now stand as false tension that ended up being reversed with ease.
<...>
Why should we care about any Stakes that are placed moving forward if all risk can easily be reversed right after? That's the main problem this situation ends up presenting. As badass as it is on the surface it just defeats the purpose of all that negative foreshadowing during the tournament. What does the story and its characters actually gain from bringing back a character that should have died?
People who are delving into how a possible revival may have been foreshadowed or made possible by following the perversities of in-universe logic continually miss the obvious point: for all narrative purposes, Ohma was better off dead than alive.
So that he wouldn't steal attention from the new leads, especially Koga who is a far more interesting and better-written character.
So that we wouldn't have dramatic tension reduced by a known precedent of consequence reversal.
So that the cheat-level Niko style wouldn't pollute and lopside the otherwise reasonable state of semi-fictionalized martial arts in the story.
I think people generally underappreciate how destructive a character like Ohma can be to an otherwise relatively coherent narrative and how the only reason it was forgivable (and, indeed, worked at all) in Ashura was
because he died at the end, thereby demonstrating the consequence for using a cheat-level technique. Cloning is one thing, but Ohma here evidently had his personality and at least some of the memories intact, clearly indicating that he was revived rather than cloned. So even if you "nerf" him post-revival, the fact that he was revived at all still essentially indicates that it's
not necessarily a one-off thing and either Ohma himself or any sufficiently powerful character—friend or foe—
may potentially be revived again in the future if plot demands so. Much like time travel, it's an incredibly powerful plot device that leads to a narrative slippery slope in which reviving a dead character becomes the most obvious solution to most problems encountered by factions as the plot unravels. So instead of coming up with ways to solve them without revival even as a theoretical option, the author will either have to come up with explanations why it isn't feasible in every particular case—or leave the series with an enormous, glaring plot hole that will drag it down until its publication ends one way or another. Which is why it becomes all the more puzzling that he even attempted something as obviously problematic as this.