Nekkko!

A white-haired anime character with yellow eyes and cat ears smiles subtly, then the scene cuts to a close-up of a dark, ruffled garment, followed by a menacing green and purple creature with glowing eyes, then a close-up of a black-haired character's eye, then a burst of white particles, and finally the white-haired character appears in a dynamic pose with a glowing white aura behind them.