If Parse targets weak points, I hope that she does irreducible damage.
I'm hoping that KNYFE will have some cards that aren't just More Stabby-Dakka, but also some stuff representing her espionage and intelligence side. Like how Trust Fund doesn't seem to match the rest of Wraith's deck, but is integral in getting her the many tools she chooses among. I'm hoping KNYFE is a bit of a scout and agent, as well as a damage-dealer. She should have some effect that gives her the equivalent of Wraith's Stealth ability, though her innate Power is probably more like F6 Wraith's Last Stand ability. Perhaps it could be "KNYFE deals 1 melee damage to any target. KNYFE deals 1 melee damage to any target." That way, it'd be similar to Fanatic, minus the two different damage types, but plus the flexibility to hit the same target or different targets, as with O-X's Rocket Punch.
For Natch, since we already have Bunker's Modes, Mr. Fixer's Styles and Tools, and Scholar's Elementals, I'm hoping for something a little different. My theory? His deck consists of a lot of one-shots which have one basic effect (perhaps just drawing some cards, or dealing a little damage, and another effect depending on which form he's in. For example:
Antelope Alertness - Ongoing. At the start of your turn, draw a card. At the end of your turn, if The Naturalist is in Gazelle Form, draw a card.
Crocodile's Jaws - One-Shot. The Naturalist deals 3/4 melee damage to any target. If The Naturalist is in Crocodile Form, a target damaged this way cannot deal damage until the start of The Naturalist's turn.
Rhino Charge - One-Shot. If The Naturalist is in Rhino Form, he deals 5 melee damage to any target. Draw five cards, then discard three cards.
Herd Instinct - One-Shot. Reduce the next damage dealt to The Naturalist by 2. If The Naturalist is in Gazelle Form, reduce all damage dealt to him by 1 until the start of his next turn. Draw a card.
Bloody Horns - Ongoing. Increase damage dealt to The Naturalist by 1. If The Naturalist is in Rhino Form, increase damage dealt by the Naturalist by 2. If The Naturalist is in Gazelle Form, whenever The Naturalist would deal damage to a target, instead he deals that much damage to all non-hero targets.
River Lurker - Ongoing. The Naturalist is immune to damage from environment cards. If The Naturalist is in Crocodile Form, draw a card whenever an environment card is destroyed. If The Naturalist is in Gazelle Form, redirect all damage dealt to hero targets by Environment cards to The Naturalist.
(For some reason, I really seem to like Gazelle form.)
Setback and the Sentinels I have no real clue on.