Time travel is, in itself, a pretty simple mechanic: If your stuff has time counters, time travel lets you either add a time counter, remove a time counter, or leave it untouched
Green-blue (or possibly Bant) is my pick for the best new deck coming out of Teenage Mutant Ninja Turtles
Skemfar Avenger is life insurance for your berserkers and elves
If a permanent enters the battlefield under an opponent's control with hexproof, indestructible, protection, shroud, and/or ward after Shay Cormac's first ability resolves, it won't lose that ability until you activate Shay Cormac's first ability again
While no new cards from Two Legends [OP-08] have been added to this deck, there have been certain cards which have restored this decks elite meta viability thanks to current metagame changes
Pokemon has a range of premade decks that can help you get into the game, starting as low as $10 with the My First Battle decks, with slightly better preconstructed decks coming in around $15-20