This boss is auto friendly, but you need an energy battery, since most of his skills (active and passive) reduce your team’s EP.
Right now the best unit for this it’s going to be Shale. It’s worth investing in her not only for this boss but for general usage since green teams will use her for a long time.
Another good option to use if you don’t have Shale built is Marillight (if your DPS units are rangers).