Koitsu
EffectUnion Effect Monster· WATER· Fairy· ★ Level 10
ATK
200
DEF
100
Once per turn, during your Main Phase, if you control this card on the field, you can equip it to your "Aitsu" as an Equip Spell Card, OR unequip the Union equipment and Special Summon this card in face-up Attack Position. While equipped to a monster by this card's effect, increase the ATK of the equipped monster by 3000 points. When it attacks with an ATK that is higher than the DEF of a Defense Position monster, inflict the difference as Battle Damage to your opponent's Life Points. (1 monster can only be equipped with 1 Union Monster at a time. If the equipped monster is destroyed as a result of battle, destroy this card instead.)
Cards named in Koitsu
Market value
Cheapest printing
$3.51MFC-080
USD, updated 15 October 2026. One price per printing, 1st Edition and Unlimited together.
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Price history
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All printings (2)
| Set | Code | Rarity | Released | Price |
|---|---|---|---|---|
| Magician's Force | MFC-080 | Short Print | 10 October 2003 | $3.51 |
| Dark Revelation Volume 1 | DR1-EN135 | Common | 19 March 2005 | - |