The simple ability to cast a bunch of free spells is something thats worth building around, and its worth putting Abaddon into other decks too
However, not being purely Innistrad, this is a set that many will prefer for its singles than its boosters, and there are a few cards you'll really want to keep an eye on to get the highest value
If you don't, create a Treasure token.Whenever you cast a spell you don't own, put a +1/+1 counter on each Scout, Pirate, and Rogue you control
You'll want to finish performing the other two dredge/draws of Cathartic Reunion first, meaning you may find Prized Amalgam on the last dredge attempt and those will see the Narcomoeba from the first dredge come into play
Once the ability is activated and the cost is paid, it's too late to stop the ability from being activated by trying to remove the creature card from the graveyard