He works with basically all the mechanics bar those that find a green dork and he instantly gives you near infinite gas
The burn spell has competed with Lightning Bolt in other formats (though Lightning Bolt usually ends up winning), and its extremely strong at swinging any kind of race, more than offsetting the life you lose to play an untapped Sacred Foundry
Then it also gives you a nice little boost if you do turn your creatures face up
While many decks focus on just a couple of keywords, its good to have a few different abilities ready to go for different situations
(He's been here the whole time.) : Create a copy of a game changer at random
Boromir, Warden of the Tower Boromir, Warden of the Tower does the work of Lavinia, Azorius Renegade to smash cascade decks with one less color and without the stax piece that make you universally hated