NRA and revived allies/vampires

Greets!

I tried to find answers for this thread and I failed. I hope you can help me on this matter.

Shmabling Hordes uses his special and attacks a vamp who makes quick work of it with Pushing the Limit. Shambo dies. Can he attempt his special attack again if it had been brought back in the same turn via Compel the Spirit or Pressing the Flesh?

The same goes for a vampire brought back via Possession?

Yes you can do the same action again. A minion who is burned and then put back in play keeps no "memories" of what he has done during the same turn.
In fact it's the main rule that allows the creation of "turbo" decks, where you bleed, burn, get possessed and bleed again.

Reyda is correct.
If your Shambling Hordes burns in turn X while using its enter combat ability, and if it's "revived" later the same turn via Compel the Spirit / Pressing Flesh, it can perform her built-in action again.