I have her maxed, she’s okay, mostly contributes on titans. Here’s my yellows ranking not considering other color heroes. I’m missing 2 of the top 3, my weakest color. 
Ranvir is conditional, pretty high if missing Miki and or Tarlak, much lower and imho not worth darts otherwise. This is based on hitting 14 titans*
Drake*
Guin
Del*
Poseiden
Ranvir (if you don’t have Miki or Tarlak
Onatel
Rana
Viv
Joon
Inari
Musashi
Leo
Justice
Ranvir (if you have either Miki or Tarlak)