Thanks 💕 as far as HCs go I'd like to dream but if we're being realistic I doubt Fyodor can be 'saved' anyhow. I think his aim is accomplishing his goal and dying. I'm 99% sure latter is what awaits him. As for former it'll depend on what Fyodor's /real/ motivation is. He might succeed. He might fail. Here's a thing:

Fyodor insists humanity as a whole is rotten. He views man as inherently selfish foolish being that's bound to cause harm, be it voluntary or not - because it's in his nature. If we roll with that then it's a man himself that's a root of wars and suffering, not abilities as he proclaims. Even if abilities are gone some other trait will divide humanity at some point and cause conflict. Everlasting peace is a pipe dream - and he must know that.

Therefore:

1) Fyodor either has personal emotion driven reasons for wanting abilities gone

2) or he's a massive hypocrite aware of shortcomings of his visions but pursues them anyways

3) or by getting rid of the abilities he'll somehow 'override' human nature (big question mark here). Religous symbolism is all over Fyodor's character. Him taking on all of humanity's sins and dying as some sort of a perversion of martyrdom wouldn't be so far fetched

In case of 2) Dazai might have a chance to reason with Fyodor, but I still doubt it'll deter him from pursuing goals he abid by for centuries. Fyodor might acknowledge he's a hypocrite but push on. He's too deep into it to back off now, best ending is to die knowing he was, at least, understood in his final moments