Solve math to power your Kai. Land enough hits to drop the boss, then climb 10 elemental arenas.
Hints are free. A 20-second timer keeps the duel moving. Streaks boost damage.
First time: solve the problem, then your Kai attacks. Keys 1–5 switch Kais. Fire melts ice, water douses lava, earth grounds wind, wind cuts water, magic bites shadow.
Progress is saved on this device.