heart of the cards mtg Defense and put those cards onto the battlefield Change of Heart - Stronghold

The same idea applies to huge spells like Temporal Trespass , which can give you an extra turn while also cascading off its full mana value

While we don't exactly know what the new firebending, waterbending, earthbending or airbending mechanics do exactly, it's safe to say that these will be tailored around four of MTG's five iconic colours

as a lot of people have stated before (reddit had a topic about these hallowed fountains) , there is very very big possibility that these hallowed fountains are just from the Theros event deck

One of them is the Rag Man, a mysterious figure who snatches people on the street in the dark of the night, illustrated by his ability that makes you discard a minion at random