The energy mechanic was introduced in Kaladesh, and it has returned a few times since, with a notable surge of energy cards in Modern Horizons 3
The History of Ward in MTG Ward appeared in Strixhaven in 2021 on four cards: Owlin Shieldmage, Torrent Sculptor, Waterfall Aerialist, and, most significantly, Sedgemoor Witch
Bloodghast (self), Oathsworn Vampire (self), Redemption Choir, Bloodline Necromancer, Carmen, Cruel Skymarcher 5 graveyard recursion
Banned in Standard after holding over two-thirds of Mythic Championship VI in his clutches, Oko has an insanely high loyalty alongside abilities that generate value as well as remove offending threats
You do need to pay attention to which land youre animating with older cards like Koth of the Hammer
It's a powerful answer to a big problem in 'walker-heavy environments from Standard to Commander