1. No Planet/Galaxy/Universe etc. busting
2.H2H Combat only
3.Bills' only used 70% of his power against SSJ GOD Goku
4.This isn't Gold saint
5. Takes place in Hyper Bolic Time Chamber (I'm sure you all know what that is)
Pegasus Seiya even without Gold Cloth could take on a Gold Saint and activate the Seventh Sense.
Even from the start he was capable of throwing a hundred punches per second.
His Pegasus Ryu Sei Kei nullified/matched Leo Aiolia's lightning plasma (A billion punches per second, basically FTL punches)
If this is purely H2H Seiya takes this with ease, the fact that each punch is probably equivalent to a meteorite and have enough damage to affects the atoms (Which I highly doubt Bills durability could handle)
Seiya handily takes this.