Union Hangar (SDKS-EN020)

When this card is activated: You can add 1 LIGHT Machine Union monster from your Deck to your hand. Once per turn, if a LIGHT Machine Union monster(s) is Normal or Special Summoned to your field (except during the Damage Step): You can target 1 of those monsters; equip 1 appropriate LIGHT Machine Union monster, with a different name, from your Deck to that monster, but the Union monster you equipped cannot be Special Summoned this turn. You can only activate 1 "Union Hangar" per turn.

spell / Field, Structure Deck: Seto Kaiba