Updated March 23, 2023 by Ryan Hay: The very silly Unfinity has been out for a bit, giving players and collectors all the time they need to open packs and chase the cards they need
This is a long rambly way of saying that Erebos, Bleak-Hearted is a very strong Sacrifice commander, but he'll end up being better in the 99 of even stronger Sacrifice commanders, of which there are a crapton at this point
Remember that if you want unique backs for the cards in your deck, you'll need to create a mirroring deck with those back designs and then check the Unique Backs option in the import dialog
With Gretchen Titchwillow, you can do both
If you have no other cards in hand, you must discard one of the cards you return to your hand
The most effective and simplest way to use Courtesan Thais is to cast her while your opponent is on Deaths Door so that way you can cast their damage spell to end the game, or you can simply force their avatar to attack your unit resulting in their avatar taking the final point of damage to end the game