Question about Gintanai

As we all know once Gintanai wins combat you have to sacrifice a creature. I'm wondering that if you have a creature that has a sacrifice ability are you able to use that creature as a sacrifice and play it's ability?

Also this could be applied to gear as well. If you have to sacrifice a gear and the one you have has a sac ability can you combine them?

No you cannot. I do not remember if the sacrifice happens immediately in the burst, or if the creature is counted as sacrificed when the ability enters the burst; either way you cannot stack the ability.

Blitser can inform you better on the technicalities.

In the short, Blaz is right. You can't gain the benefit of a sacrifice ability with Gintanai's ability.

Think of the burst for this situation. Gintanai starts one off at the end of combat and immediately makes you choose a creature to sacrifice. Costs for abilities added to a burst are taken before the burst resolves, so before you even get the option to sacrifice that creature with its own ability it'll be removed from the board.

This is now just hypothetical, but say the cost was paid when each card in the burst resolved. Gintanai would be added first, then you'd add the desired sacrificial creature through its ability. Since the burst resolves in reverse the creature you're sacrificing would have its ability resolve, then Gintanai would have nothing to pay the cost of its own ability. Since the cost to keep him on the board was not paid Gintanai would then be destroyed.

----------

Edit: If an ability passively activates when a creature is destroyed or sacrificed it will work. It just can't be an activated ability.

Are there any creatures with those kinds of passive abilities?

He's talking about something like Illexia, Lore AC, or Enre-hep that gain MCs when a creature is destroyed.