The current CW abilities - and even Ice Ward, back when it was in the game - both don’t give feedback and are more or less random luck. Hopefully this would change that.
Concept: Give CW something more or less unique to him, while still letting him help out the rest of his faction.
Passive Abilities:
Caster: Your abilities do not count as visits.
Day Abilities:
Study Notes: Select a dead player to examine. You will be able to use Channel Spell from them. Does not work on any Special or Killer classes. Infinite Charges.
Night Abilities:
Channel Spell: Use a dead player’s ability. May only be done once per dead player, only be used after Study Notes was used on that player, and only if that player had charges remaining on their ability. Infinite Charges. (Obviously, “griefing” abilities like Mind Warp or Frame should be unusable. Defiled and Facelifted corpses have their abilities fail - maybe the CW is said to have been occupied, or their charges are both depleted. I’m not sure if the engine can actually do this sort of thing, and it’s probably massively overpowered anyway.)
and either
Whirlwind: Any players targeting your target player will instead target themselves. You can target yourself with this ability. You may not target the King. Does not affect occupy-immune targets. 2 Charges. (If a death results from this, the CW’s death note will be used. This lets the CW prevent visits or save people from them, without getting some random other guy killed in the process - but also disrupts investigations entirely. A bit like a really annoying Knight.)
or
Ice Ward: Nobody will be able to visit your target tonight. You can target yourself, but not the King. 3 charges. (Or, again, a one-day cooldown. It could also just give death immunity, with Clear Mind taking up the other half of the visit protection - I’d recommend Whirlwind, but this is still an option.)
Regarding Sage:
His abilities are currently powerful enough when he’s working with the Assassin - being able to deny healing or guards either indirectly or outright makes him one of the more useful converts, depending on the situation. I’d leave him with Tornado instead of Whirlwind - both effective in their own way.
Also, yes, I’m aware that this is enough of a rehaul that the CW feels almost like an entirely new class, but that didn’t really stop the devs before. Hopefully it would make CW feel more ‘important’, being able to take on a dead man’s role for a night - Investigate someone suspicious, or Heal a single case of poison. This probably also mean he has to be Unique again.