@Caiiro27 That’s a genuinely difficult question, because matchups matter. Who fights whom, in what environment, with which equipment, and at what point in each character’s development makes a massive difference.
Since you asked for a list, here’s a ranking of the reader-characters at their absolute strongest, ordered by power:
1. The Sorcerer’s Apprentice (Death Vow)
2. trc; Nacht (Canis × Gallus × Felis × Equus – 100%)
3. Angel (EOS, with Soul Transfiguration)
4. Telekinesis Reader (EOS)
5. Genius (Peak, Will to Live)
6. Rat (Peak, On the Brink)
Before this list looks strange, a few important clarifications:
This ranking is based mainly on statements and feats. In theory, Angel could one-shot most of the others — however, he can’t reach ranks 1 or 2 because those characters are simply far too fast and would overwhelm him with constant pressure.
A similar argument applies to the Telekinesis Reader from Hold On. At the very start of a fight, he could theoretically tear an opponent apart instantly. But again, ranks 1 and 2 are far too fast — and Angel (rank 3) cannot be killed by him.
Ranks 5 and 6 required the most thought. The Rat has shown stronger combat feats so far (against Kickin, against staff members), but at the end of the day, he’s still a broken experiment. I believe he would lose to the Genius in a close fight — roughly 70/30 in favor of the Genius.
Overall, I’d still say that The Sorcerer’s Apprentice in the Death Vow state is the strongest character I'll ever write — not just because of raw power, but because of what’s at stake, and more importantly, what he has to give up to wield that power.