Hm. Yeah... Now that I think about it, Thousand Kings might be my most powerful. It's a one thousand hit combo, as the name suggests. But the thing about it is, each hit deals the squared amount of damage the last hit did. So, to give it a numerical value...

If the first hit deals... Oh, 12 damage. The next hit will deal 144 damage. The next hit will deal 20,736, the next hit will deal 429,981,696, and so on and so forth. It gets a crazy amount of damage on, and costs surprisingly little energy...

Dark Forge... It's a bit hard to use. It requires a lot of concentration, but is crazy powerful at its strongest. It gives me powerful psychic powers, which can be precise enough to control things smaller than the molecular level, so I can literally split atoms within the target's body. But the more precise I am, the more concentration it takes. So I basically disassemble my opponent on a molecular level.