Test Tiger's effect on Opponent's Gladiator Beast?

Question

If I use Mind Control/Brain Control/Change of Heart on my opponent's Gladiator Beast monster, I would gain control of that monster and I would be the "controller" of that Gladiator Beast monster.

After that, can I special summon my Test Tiger from my hand? (I DO control a Gladiator Beast card)

If I can, can I use Test Tiger's effect on my opponent's Gladiator Beast monster? (I am the controller of that Gladiator Beast card)

If I can, do I send my opponent's Gladiator Beast monster to MY deck or my opponent's deck? (I am still the controller of that Gladiator Beast card, so according to Test Tiger's effect, it SHOULD be me)

Situation:

Opponent has Gladiator Beast Bestiari on the field, no other cards.

Turn Player activates Brain Control, target Gladiator Beast Bestiari.

Turn Player special summons Test Tiger from his hand.

Turn Player activates Test Tiger's effect to send Gladiator Beast Bestiari to Turn Player's deck.

Special summons Gladiator Beast Laquri

^would the above be playable?

Answer 1

i dont think u can send it to your deck, so u cannot use its effect.

but honestly, im not sure, but thats a very good question.

but no matter what, u can still special summon test tuiger because you have a GB o your side of the field

Answer 2

Ok.

I believe that You CAN make that move - Take your opponent's bestiari, special summon test tiger, then tribute it to send the bestiari to YOUR OPPONENT'S deck to special summon a GB of ur choice (darius, murmillo, secutor, laquari) the resulting GB will get its effect.

Hope this helped!