Last but not least, you have some pretty strong options late game thanks to Elsa Spirit of Winter, Madam Mim Purple Dragon, as well as a fantastic attacker in the form of Tinker Bell Giant Fairy.
The only downside of this is when you hit a land card you need, because you cant pay its mana cost to flip it
The key thing with Ureni is unlike Craterhoof, it prevents the crack back if you are unable to finish them off that turn
It also has an activated ability where you can pay one generic, one blue, and one red mana, and tap it to draw a card and discard a card
In Commander, where games are a lot slower, Krenkos ability really shines and can create a board thats almost impossible to deal with
I was killed a turn or two later by another player and I was really just happy to have found a way to cheat death once and kill someone before the game was over