This is a special action, not an activated ability. With the new rule, companion players must go through an additional step and additional mana to get their precious kitty or other companionslike my favorite Yorion, Sky Nomadinto play
The attachment only ends if something explicitly unattaches the Equipment or attaches it to another permanent (such as from you activating the shackle ability again)
The issue crops up when none of your opponents are playing green
2 Likes deltazero July 7, 2020, 10:41pm 7 I imagine a base set unlimited pack with Blastoise artwork
This can happen one of two ways: (1) the door becomes unlocked on the battlefield or (2) the door becomes unlocked as the Room enters the battlefield because you cast the corresponding half
The Team Up set is from Sun & Moon era, released all the way back in 2019 (which doesn't actually seem that long ago!)