Abizo the Possessor

[Sleepy]

 

2 Union Monsters

It is always treated as the correct target for Union Monsters. When Summoned: You can target 1 Union Monster from your Deck or Graveyard; equip them to this card. If the Union Monster change ATK or DEF, this card loses 1000 ATK.

 

[Cuatal]

I'm not sure how this card would work, when all union monsters say "A monster can only be equipped with 1 Union Monster at a time"
Even though I liked the idea of supporting union card, a card that would require polymerizaiton to play, sounded so slow at first. But then I looked up the union monsters and If you bypass the part that says only 1 union monster can be equiped to a monster: You get a 7000 ATK monster (with Doitsu and Koitsu) which is immune to destruction once by giving up 3000 ATK points (which is nothing if it will have 4000 anyway.) and 1 time immune to battle destruction by giving up 2500 ATK points. And then, he has piercing damage with all that point. AND is a level 4 so easily could be used to get triple overlay Rank 4 monsters even if you wouldn't like that 7000 ATK points. 
What's more: you can monster reborn him to do the same thing again. No.

[Sleepy]

I'm not sure how this card would work, when all union monsters say "A monster can only be equipped with 1 Union Monster at a time"
Even though I liked the idea of supporting union card, a card that would require polymerizaiton to play, sounded so slow at first. But then I looked up the union monsters and If you bypass the part that says only 1 union monster can be equiped to a monster: You get a 7000 ATK monster (with Doitsu and Koitsu) which is immune to destruction once by giving up 3000 ATK points (which is nothing if it will have 4000 anyway.) and 1 time immune to battle destruction by giving up 2500 ATK points. And then, he has piercing damage with all that point. AND is a level 4 so easily could be used to get triple overlay Rank 4 monsters even if you wouldn't like that 7000 ATK points. 
What's more: you can monster reborn him to do the same thing again. No.

Hmmm yeah, the "1 union at a time" clause... I should probably decrease this card's use. Such a basic feature slipped my mind.

 

You are forgetting about Instant Fusion, btw. Polymerization is not needed. You originally made a 4500 ATK piercer that can destroy 1 S/T when it attacks and survives battle destruction twice.... if you equip it with Koitsu + Burning/Freezing Beast.

 

Though you are right, it needs a few changes here and there.