Spell • Cost: 3
Gain control of an upgrade, ongoing spell, or building card (not add-on).
Purple • Future Magic
You gain control of the card as long as it remains in play, for the rest of the game. If it's destroyed, it will go to its owner's discard pile, not (necessarily) yours. If something "returns" it to play such as Geiger or Pasternaak's max level abilities, it "returns" to play under your control because you were the one who last controlled it. — Sirlin, 03/11/16
A "building card" does not mean a base, an add-on (such as the Tower or Surplus), and it does not mean your tech I, II, or III buildings. It does mean building cards that players can have in their decks such as Rickety Mine, Graveyard, Firehouse, etc. — Sirlin, 03/11/16
If an enemy unit has Spirit of the Panda attached and you Assimilate Spirit of the Panda, you now control it. It remains attached to the enemy unit and that unit still gets +2/+2 and gives its ctonroller 1 gold when it attacks. But now during YOUR upkeep, YOU get the Healing 1 effect. — Sirlin, 09/22/16
If you use this to steal an ongoing channeling spell such as Two Step, but you don't control the appropriate hero to channel that spell, it's immediately discarded. — Sirlin, 03/11/16
If you use this to steal your opponent's Graveyard, you will be able to play units owned by your opponent from the Graveyard. You can always play tech 0 units from the Graveyard. If you have a tech I building, you can play any tech I units from the Graveyard. To play a tech II unit owned by your opponent from the Graveyard, you must have a tech II building with a matching spec. This is only possible if you are playing some of the same specs as your opponent. You cannot name a spec other than your three specs when building your tech II building or tech lab. — sharpo, 09/22/16