Ive had a Legacy Affinity deck on the side ever since my friend showed me how quickly you can kill someone with a turn-two Tezzeret, Agent of Bolas in that format
Gameplay-wise, Altered features two combat lanes (called Expeditions), each led by a Hero, and uses a flexible resource system where cards can be used as energy, kind of like what you see in Lorcana or Pokmon
I would try my luck in submitting them to beckett
Call is a little too middle of the road, rather like Blade Splicer as 3/3s for three don't do all that much to the game
Some cards stand out due to their powerful abilities, like Rainbow Dragon or Monster Reborn for monster revival
For decks where you need to find specific cards to set up quickly, Lucky Helmet is an immensely helpful Tool to have on hand