When this card is Normal Summoned: You can target 1 Union monster in your Graveyard; Special Summon it. Once per turn, you can either: Target 1 Machine-Type monster you control; equip this card to that target, OR: Unequip this card and Special Summon it. Your opponent cannot target a monster equipped with this card with card effects, also if the equipped monster would be destroyed by battle or card effect, destroy this card instead.
The repetitive summoning of this monster can easily get the fusion materials for "XYZ-Dragon Cannon" from the graveyard and protect them.
Equips self from field
Treated as Equip Card / Cannot be targeted by card effects / Redirects destruction / Destroys itself
Special Summons from your Graveyard / Special Summons itself from your Spell & Trap Card Zone
this card certainly helps to make union viable but still not enough. u need at least 2 turns to pull it off and even then it is stil meh. so next time we need a powerful magic cards to make machine union interesting