Poison, basic is in the TT equipment table, though there's a Con save to avoid it. By memory BG3 reduced wyvern poison to 3d6, but again no Con save.
Mid level rogues get to half incoming attack damage (works best 1 on 1) and evade Dex AOE for no damage. Both these synergise well with traps and common battle scenarios. Not to mention the sneak attack dice keep stacking every odd level.
Note: sneak attack is once per turn, not per round. So the battlemaster Commander's strike, allowing you to attack on _their_ turn qualifies for the dice. Same with Riposte and similar actions outside your turn. Savvy rogue players working with the party can rack up impressive spike damage.
At level 11 they get Reliable talent - and together with Expertise, can potentially break the skill system. OMG, a Cha rogue with Expertise doesn't need to even roll to beat the dialogue DCs. But will BG3 still have 1's fail? In TT, they don't, and if they go this route, the social-savant rogue will destroy dialogues - so long as they can get a single word in.
Probably no point talking about higher level Blindsense or Slippery mind.
I really like Assassin's level 9 Infiltration Expertise where they create alternate personas. Dunno if Larian can implement, but it'd be super-cool creating someone to be in city of Baldur's Gate.
