How would Jon Irenicus, Shattered One work with Blood Pet's ability?

Question

I'm building a Jon Irenicus, Shattered One deck and wanted to know how his ability to give a creature "this creature can't be sacrificed" would work with something like Blood Pet or even Mausoleum Wanderer? Would I just be unable to use the ability? Would I make infinite black or counter spells for free?

I also wanted to confirm if he can actually end the game in a draw with some like Merchant Ship or Pirate Ship if anyone has an answer? I believe it would because of a mandatory loop but want to be sure.

Answer 1

No, you can't activate those abilities.

If you can't do something, then you can't pay a cost that requires you to do that thing. So, if you can't sacrifice a creature, then you can't activate an ability that requires you to sacrifice it as a cost. In addition, Jon Irenicus's ability also causes one of your opponents to control the creature, so you wouldn't be the one activating the ability, they would.

Yes, the ability does create an infinite loop that draws the game with Merchant Ship or Pirate ship if their controller doesn't control any Islands. The ability triggers, and then resolves and does nothing and then triggers again, forever.