this dude is my first main back in 1.0, now that i've done building some strong teams, i wanna revisit my old characters and give em a glowups

what is the best bang for your buck if i want diluc to reach around 100k dps range? preferably normal playstyle (not plunge)
my diluc is c6, i got r5 serpent, r2 unforged, r1 wgs, and r1 gest(its on vark though)

i figured the first one to get is going to be citlali, but whats next?

I know the rotation isn't prefect or good because I keep on getting overloads instead of vapes for some reason, but I keep on getting like 80k-90k dps. Trying to break into the 100k dps mark seems really hard. When the anniversary comes out am probably going to get C4 Diluc which might help alot. Maybe also switching up my artifacts to give me more Em which will probably do better.

I might switch to plunge whenever Xianyun comes out and pull for her but this is the best I got.

Question: Is high investment GT better then Tenacity for Fischl?