Using this card in a Kaiju deck with Moon Mirror Shield can easily dish out 4000-5000 damage every turn. As well as being able to use Moon Mirror Shield equipped to a Gameciel, the Sea Turtle Kaiju to create an unstoppable monster.
You can use this card with "Limiter Removal" when your opponent attacks to destroy a Level 4 monster.
Use "Shien's Spy", "Mystic Box" or "Creature Swap" on "Koitsu" and give it to the opponent. You can also use "Give and Take" to Special Summon it from the Graveyard. Then attack it with this card for at least 5000 damage. For a simpler combo, just Special Summon "Grinder Golem" to your opponent's field in Defense Position and attack it for 4000 damage (you will need to have this card on the field since last turn).