The Power of Mako is the alternate EX Mode for Cloud while he is wearing the Advent Children outfit, which enables him to equip the completed Fusion Sword. However, it is identical to his normal EX Mode otherwise.
Mako Might is one of four Record Materia that can be acquired with Cloud in the fighting party. The player must advance Cloud past level 65 with his first two Memory Crystals and must also have acquired the SOLDIER Counter Record Materia in a prior battle.
When equipped, a character bearing Mako Might will begin battles with one Soul Gauge charge completely filled.