After the Valkyrie brought Alice to Wotan, he had revealed to her that her necklace Alberich had stolen contained a secret the could bring an end to the world. He ordered her to find the necklace and give it to him. He then turned Alice into a Valkyrie, and along with the other Valkyries, she set out to defeat Alberich.
Once Alice had defeated the dwarf, she, along with the other Valkyries, went back to Wotan and gave him the necklace. When he clutched the necklace, the sky turned red and fire rose beneath the mountain where the palace resided. He revealed his plan to reborn the earth from ash. An enraged Alice stood up against him and used her spear to stab him in the eye, killing him in the process.
Wotan was a giant and wore an all-white ensemble. He had long, white hair and beard, and a white crown atop his head. He wore white robes and had a white staff.