I don't think Containment Priest if the format-warper that True-Name Nemesis was (and in some ways continues to be) but I think its going to be played far more than Toxic Deluge, which is generally a sideboard one-of
The Sword can be activated for a massive eight-mana to kill the player that takes combat damage from the equipped Sword
At the beginning of your upkeep, double the number of +1/+1 counters on Lily Bowen if its power is 16 or less
In most formats, losing life can be detrimental, but in Commander it is much more easily worked around, making the drawbacks of both cards not bad
This was one of those cards that a lot of decks were on the edge of playing, either because they couldn't quite get threshold reliably or they didn't want to splash one of the colors, inviting them to play a high-risk but high-reward game with their mana bases that both cost them games and won them games they had little right to win
It's pretty awesome to make a Leviathan or Kraken out of nowhere on someone's end step, but it's even more amazing when you turn your Cryptoplasm into a second one on your upkeep