Edison format ruling
Y-Dragon Head
Card effect (current official text)Once per turn, you can either: Target 1 "X-Head Cannon" you control; equip this card to that target, OR: Unequip this card and Special Summon it. A monster equipped with this card gains 400 ATK/DEF, also if the equipped monster would be destroyed by battle or card effect, destroy this card instead.
Rulings
(1) Once per turn, during your Main Phase, you can equip this card to X-Head Cannon you control as an Equip Card, OR unequip it to Special Summon this card in face-up Attack Position. (2) While equipped to a monster by this effect, that monster gains 400 ATK and DEF. (C) (A monster can only be equipped with 1 Union Monster at a time. If the equipped monster would be destroyed by battle, destroy this card instead.)
- If Y-Dragon Head's ATK is doubled with Limiter Removal, and then Y-Dragon Head is equipped to X-Head Cannon, Y-Dragon Head is not destroyed at the end of the turn.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.