The devour mechanic doesn't require all that much design as trading creatures for +1/+1 counters provided plenty of interesting game play
Pokmon who have sat on the board for at least one turn can be freely upgraded by placing an Evolution on them, which have larger health pools and stronger moves at the cost of usually being more Energy intensive
Spider-Sense I feel something tingling
Legendary Creature - Human Knight Shaun, Father of Synths Whenever you attack, you may create a tapped and attacking token that's a copy of target attacking legendary creature you control other than Shaun, except it's not legendary and it's a Synth artifact creature in addition to its other types
Exact wording of the official rules: "When you play your next-to-last card, you must yell 'UNO' (meaning 'one') to indicate that you have only one card left"
On your post-combat main phase, you can pay life equal to the number of players that were dealt combat damage this turn and draw that many cards