Have you thought of Pack Rat as a cage enabler? With Training Grounds it B + discard a card (maybe the creature you want to cage) to make a token, trigger the ETB, exile the token and then cage something. Pili-Pala also works as a backup Staff of Domination. Entomb and Intuition allow you to get the artifact combo pieces into your Graveyard.

Pack Rat offers a good way to trigger the ETB, but it doesn't offer much protection to Mairsil and it's kind of a bad card by itself.

Entomb, Pili-Pala and Intuition are now added!

@ Quicksilver Elemental: You actually only need to use the ability only once. The newly gained abilities are not bound to the once per turn restriction anymore.

Yes, I figured that out later but forgot to update combo description, thanks!

Why include pestilence souleater? I don't see any real reason to include it aside from just flat out giving infect for combat. And crucible seems like a rather odd inclusion. It doesn't seem like you'll be generating much value unless you can effectively discard land every turn.

Windfall, dreamscape artist, jace's archivist, cathartic reunion, daretti, grixis battlemage, thirst for knowledge, mercurial chemister...

I've playtested this list recently and Crucible was one of the last changes to the deck because it is actually easy to have lands in the grave. I didn't put the manabase here but there are some pretty useful with sacrifice abilities. It might not be clear by looking without some testing, as I myself didn't see the need for it until I played a few hands.

And about pestilent souleater it's intended to kill by infect. Together with Jodah's Avenger , Stormchaser Chimera, Morphling, AEtherling and/or Drana, Kalastria Bloodchief it can be dealy. But you are right, there only utility for this card is to be caged by Mairsil. It is possible that it's just not worth it, but I'll give it a try.

How about Teferi, Mage of Zhalfir + Knowledge Pool. It creates a lock to where opponents can't play anything. Mairsil can copy both and be a one card lock.

I just realized that it says activated, not triggered or static. So my above comment is incorrect. Please disregard. Still two good cards though.

Hi mate,

I've been watching your list ever since you added it here on tappedout. One thing I noticed in your description is that " If you copy again before activating them, you will have 4, do it again for 8 and so on. With four blue mana you can have 16 copies of each of your abilities!". You shouldn't have to copy again BEFORE activating them. For instance, you could use Quicksilver to gain two instances of each ability, use those, and use quicksilver again to gain two new instances of those abilities. Or am I missing something?