Each spell with overload has a target, but if you cast it for its overload cost rather than its mana cost, you can change the word "target" to "each," or what the Izzet used to call "restraint." Remember that a spell with targets can fail to resolve because its targets become illegal, but once you overload it, it no longer has targets, so it can no longer fail to resolve this way
You can read more about the set below and when you can snag them
A more generic iteration of the deck would probably run more sacrifice outlets, and I did consider running Phyrexian Altar as a way to get Teeg out of the way and give me 1 mana
Furnace Layer Plane: New Phyrexia When you planeswalk to Furnace Layer or at the beginning of your upkeep, select target player at random
It's an open-ended question, but if you can't answer it everything else in the deck won't matter
Its an auto-include in any ooze typal build, but its tokens fit in a Duskana, the Rage Mother build