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.