>>532065921
>how can i tell who is a buster?
Literally just look at your own servants, or look up servants on the wiki

>>532065921
>NP 3 times
Here's a simple setup with your Raikou, Koyan, a support Koyan and oberon
>turn 1
>give her a craft essence that has her start the battle at 70%+ NP
>use second skill (after upgrading with her strengthening quest) to charge to 100%
>use both koyan's 3rd skill on her, NP
>turn 2
use your koyan and a friend's support koyan to charge her to 100% with her first skill NP again
>turn 3
>use Raikou's 2nd skill again to charge to 30%
>use your plugsuit mystic code to switch in oberon, use all his skills on Raikou to 100% and power her up, NP again

All your skills need to be at max to pull it off. It might be even easier to do it with Rider vinci and two castorias, since her arts NP lets her refund her NP gauge. Right now for this kind of loop farming your best options are Gilgamesh, Eresh, Vinci and Raikou, your Raikou and 2 Koyans + Oberon should be able to clear nearly all farming nodes. If you like her, summer Melu is a good generalist arts looper too.