The biggest downside is the price, which is heftier than a Standard set
If a spell or ability that targets that creature would cause a source to deal damage to that creature this turn, prevent that damage
This can look like a targeted ability that gives deathtouch like Qarsi Revenant, typal keyword anthem effects like Death Baron, triggered effects like Ankle Shanker, and even a few of the best equipment with deathtouch like Basilisk Collar
Elves of Deep Shadow gets a shout-out for fixing mana, but all the 1-mana dorks are incredible
As a 4-mana 3/3 with a potentially three-target Oblivion Ring, Haytham makes for an interesting Azorius commander if you feel like being a pain to your assassin-pilled friends.I Its Knight anthem alone isnt really enough to build around, especially when it can slot into the 99 of almost any other Knights deck