User blog comment:SpartenX/new legend world cards/@comment-24965906-20140925064014

For Power of Mythology,

Judging by the number in the effect, it appears to add 5000 Power (the same symbols come in the same order for other Power + whatever cards), but no Counterattack, while the other two are what we know, Penetrate and a Negate. And it's like Tyrant, where you pay 2 Gauge and apply the effect you want.

Just a guess, I can't read Japanese. :/