Compare this to Sun & Moon and Sword & Shield , where there were a few Secret Rares, all of the same Rainbow Rare style
ACE SPEC cards are always extremely powerful thats why you can only have one per deck but being able to change the tides of battle after a Knock Out by cutting your opponents hand in half is ridiculous
Stet, Draconic Proofreaders white ability helps to make sure that the damage will resolve
Convoke has made an appearance in several sets on one-of designs, including Duskmourn: House of Horror , Modern Horizons 3 , and Marvels Spider-Man , as well as many Commander precon designs
Maester Seymour starts off as a , but he has a dangerous Monstrosity effect, and also grants a creature you control X +1/+1 counters, based on his power
It's an incredibly defensive card for red, and can be tricky to work around unless you're including it in some kind of goad deck, but even then you wouldn't want this as your commander