Cannot be used as a Fusion, Synchro, or Xyz Material for a Summon. While this card is face-up on the field, it cannot be Tributed. When this card on the field is destroyed: The controller targets 1 Spell/Trap Card they control; return that target to the hand. You can only control 1 face-up "Green Duston".
Cannot be used as a Fusion Material Monster / Cannot be used as a Synchro Material Monster / Cannot be used as an Xyz Material
I wonder why did they release a card so broken. The restriction on Dustons is really insane, over the top. Putting 3 of these guys on the opponent's board is a guaranteed field lock. There are very very few cards that remove a Duston from your field by summoning a monster.
Stall is degen everywhere. And while that spell and House Duston are the broken easy way of putting them on opponent's board, they aren't the only way, as cards like "Give and Take" exist. So they aren't "box filler", they're hardcore stall burn support.