Might be a bit early to call this but imo she is one of the strongest ST servants in the game in terms of challenge quests. Her NP damage boost rampup is so huge and easy to access.
Servant info graphics by FGOWIKI：https://fategrandorder.fandom.com/wiki/Wandjina
Servant damage sheet by ratentaisou : https://docs.google.com/spreadsheets/d/1OTrMARN9I06zD_jIhGdmHFWpkePoSWv_xgEk3XPzZWY/edit#gid=1993499094
0:00 Skills and NP
10:24 Farming
12:42 High difficulty