Ive hunted daora nearly 30 fucking times and I still dont have a damn investigation for him.
And hopefully the GS's charge slash buff is good enough to make a crit draw build on par with tcs

Vaal Hazaak was a joke other than his BS ranged attack.

Yeah and even that isn't that bad once you know about it and have either a light weapon or a block build.
The only other issue in the fight is the damn nazi-gas he covers 99% of the map in. It gives you that supid AIDS-blight so you're constantly chugging nullberries so in the case that anything he does actually ever hits you somehow you don't get 1-shot.  Not to mention Blight-resist does not cover it, Torches can't blow it away and anyone without dragonseal (see: literally every single bowgun user) has to deal with getting gassed for the whole fight.

Overall Vaal is probably the worst monster in the game. It's just  a piss easy Dora The Explorer tier obstacle with 2 crappy gimmicks to cheese-kill newbies and occasionally experienced hunters once every 30,000 years.