Yu-Gi-Oh! Nightmare Troubadour: Intermediate Puzzle 12

Intermediate #12 Extra Large Activate Megamorph and select your Giant Red Seasnake.

Activate Megamorph and select Great White.

Switch to Battle Phase.

Attack Blue-Eyes White Dragon with Mystical Elf.

Attack Blue-Eyes White Dragon with your Giant Red Seasnake.

Attack opponent's Giant Red Seasnake with Great White.