I've managed to get to him and have the following team;
Leader: Luminara 7* G7
Qui-Gin Jinn 5* G7
Jedi Consular 6* G7
Mace Windu 5* G7
Ahsoka Tano 5* G7
I managed barely quarter of Yoda's health?
He one hit KO'd Tano right off the bat, then hit someone else and does his annoying immunity to the next strike. The trouble is he then essentially one hit KO's most people and keeps doing the immunity after so 90% of my strikes can't hit him. All my gear 7's are like one piece of Gear 8, so I'm not sure what else I can do to actually do more damage? Surely I don't need to farmt o Gear 9!?