Union time

|Vulcan Fist|???|????|Machine/Union/Effect|Fire|3|700|500|Once per turn, you can either: Target 1 monster on the field; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. when that target attacked: You can send 1 Union Monster equipped to that target to the Graveyard; that target gain an additional attack but when it uses this effect, any Battle Damage inflicts is equal to the ATK of the Union Monster sent by this effect instead.|

|Heavy Machine Transformer|???|????|Machine/Synchro/Effect|Dark|3||1900|400|2 Level 3 Machine-Type or Union monsters. Once per turn: You can detach 1 Xyz Material from this card; equip 1 Union monster from your hand or Graveyard to this card. If this card would be destroyed by your opponent's card: You can send 1 card equipped to this card to the Graveyard instead.|

|Clearshield Enforcer|???|????|Machine/Union/Effect|Water|3||600|1500|Once per turn, you can either: Target 1 monster on the field; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. While equipped by this effect, that target cannot be targeted for monster effects your opponent controls. Once per turn, that target cannot be destroyed by battle.|

These are all quite quite nice.

For Heavy Machine Transformer, I would say:

Once per turn: You can detach 1 Xyz Material from this card. Then, you can equip 1 Union monster from your hand or Graveyard to this card.

cause it's kind of like Zombie Master in that if you don't have any in your hand / graveyard, you can't activate the cost (even if deattaching WOULD mean you have a target)

Clearshield Enforcer should say "The target cannot be targeted by a monster effect, except Union Monsters", cause Unions continue to target their target. If that made sense

|Turbulence Arm|???|????|Machine/Union/Effect|Wind|3||1000|400|Once per turn, you can either: Target 1 monster on the field; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. While equipped by this effect, during the end of the Battle Phase, if that target attacked: Target a number of cards your opponent controls equal to the number of attacks that target declared; return those targets to the hand. Once per turn, if that target is targeted for an attack: You can target the attacking monster; negate that target's attack.|

|Heavy Armory Mechanical King|Machine/Effect|Dark|8||2700|1800|Cannot be Normal Summoned. Must first be Special Summoned by Tributing 1 face-up monster equipped with 3 or more Union monsters. When this card is Special Summoned: Target a number of Union monster in your Graveyard equal to the number of Union monsters equipped to the Tributed monster; Special Summon those targets. This card gains 100 ATK for each Union monster you controls and in your Graveyard.|

|Scrap Gear Armor|Machine/Union/Effect|Earth|4||800|1600|Once per turn, you can either: Target 1 monster on the field; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. While equip by this effect, that target gains 400 ATK and 800 DEF. While equipped by this effect, during each End Phases of your turn: Add 1 Level 4 or lower Union monster from your Deck or Graveyard to your hand. (If the equipped monster would be destroyed, destroy this card instead.)|

|Apocalypse Claws|???|????|Fiend/Union/Effect|Dark|3||1000|200|Once per turn, you can either: Target 1 monster on the field; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. When equipped by this effect, that target gains 500 ATK. When that target is targeted for a Trap Card or effect your opponent controls: Your opponent can discard 2 cards from their hand otherwise, negate the activation and if you do, destroy it.|

|Prominence Hand|???|???|Fairy/Union/Effect|Light|3||800|600|Once per turn, you can either: Target 1 monster on the field; equip this card to that target, OR: Unequip this card and Special Summon it in face-up Attack Position. When target destroy a monster by battle: Gains Life Points equal to that monster's ATK. When that target is targeted for a Spell Card: You can send 1 card from your hand or side of the field to the Graveyard; negate the activation and if you do, shuffle it into the Deck.|