If a creature such as Clone is entering the battlefield under your control, there will be two copy effects to apply: the creature's own and Mystic Reflection's
Cycle of Gearhulks Returning to MTG from the original Amonkhet are a Gearhulk cycle, this time in two colors with a harder cost
Against the blue decks you generally want to save it for their end step, against the aggro decks you want to combat step it, while against the midrange decks its often best used in the upkeep just to tap down lands (Tron literally cant interact at anything other than Sorcery speed)
Oroku Saki, Shredder Rising This is a Cast Down and Snuff Out proof impersonation of Ninja of the Deep Hours
This looks like a minor change on the surface, but it really opens up a lot of possibilities, in graveyard-focused decks in particular
I like to keep some unaltered precons around for when I play more casually, and Limit Break is the perfect candidate for this