I couldn't finish 'em. Looks like this's gonna get complicated.
The Tangata encounter plays like a mixture of the Firemane and Thunderclap Guivre encounters. He will start with Double Smash, a basic cone-shaped AoE, and at 50% will add Straight Punch, an instant melee added that heavily knocks back the target.
At 90%, 70%, 50%, and 30% HP, two torches in the room will start spawning Damantus and Noxius wisps like in the Firemane encounter. Should they reach Tangata, they will explode with Scorched Earth. During the 90% and 70% phase, Tangata will take after the Thunderclap Guivre, becoming immune to damage, standing in a patch of fire that inflicts Burns on anyone foolish enough to stand in it, and bombarding the party with a Firewater AoE. Three Fire Sprites will spawn one at a time, and all three need to be killed to remove Tangata's immunity. In these phases it is possible to stop the Damantus and Noxius spawns prematurely by killing the Fire Sprites quickly.
During the 50% and 30% phases, Tangata will no longer use Burns, summon Fire Sprites, or gain immunity, but will move freely and start knocking around the tank with Straight Punch, making these stages much more chaotic. As the torches which spawn the wisps are random, the tank should try to be aware of which torches are active and keep Tangata as far away from them as possible.