They are reprinted cards with unique tentacle-like decorations shooting out from their frames
Summons will also appear in the set
Let's see how well the stock list pulls off its goals: Counter Blitz is all-in on Counters and does what it sets out to do well: I count 38 cards the put counters on either themselves or other cards, nearly all of these are +1/+1 counters but there's a bit of other stuff too (4 summon creatures put lore counters on themselves like Summon: Valefor)
Still, I think the upfront cost as well as the fact that you need to untap with it before you can start exiling stuff makes it a tougher sell than other options as far as graveyard hate goes
He has a very high ink cost of 7 for summoning him, but that high cost is worth it as he has high stats and incredible abilities
Hence why Rydias called Summoner of Mist. In Final Fantasy 6 , Terra is half-Esper (the games unique term for a race of summons that have their own plane and culture), so her dual nature quite literally makes her a Magical Adept capable of transforming into an Esper herself and copying a summon on the board