Kento Nanami

If Nanami hasn’t been exerted this turn, you may exert him as he attacks. When you do, double his power until your endstep.

Ratio Technique — {r}{r/w}{w}: As Nanami attacks, defending player chooses a number between
1 to 10, then roll a d10. If the result is the chosen number, double Nanami's power until your next combat step. Activate this only once and during
your combat step as Nanami attacks.