Screw timing.

Two players can easily pull off an -aga spell.

Three, two (player one releases on two), one (player two releases).

Bam, Firaga sets everything aflame.

Just count down in timing, it's easy.

With four players, we were pulling off the -aga +1 spells every time, not that we used spells much.

Just gave up casting and all ran into attack the boss, while the Yuke character carried the chalice and healed us.