The floor is solid even without a chase hit
Cephalid Coliseum The pain on Cephalid Coliseum isnt great, but as a cEDH option to dig for cards quickly, you can do worse
If Tellah is no longer on the battlefield when its ability resolves and eight or more mana was spent to cast the spell that caused its ability to trigger, the ability will still deal damage to each opponent
Red Dungeon Cards Venturing into the Dungeon Cards Kick in the Door isnt the best venture card and only really works if you have enough mana and a creature to cast it with
If it tries to put an instant or sorcery card onto the battlefield this way, that card remains in its current zone instead
There are dozens and dozens of various error cards that have popped up over the years, so it may take you a while to check your collection for them, but it may be worth it if you wind up finding one