Kaijudo: Clash of the Duel Masters (2012)

S01E19 Heart of Darkness - Part 1

Allie spearheads a mission into the realm of the Darkness Civilization, where her team faces relentless assaults that severely impact their numbers. As they navigate through perilous terrain, they push onward toward the fortress of a powerful Darkness Lord, infamous for his formidable control over the land.