Summer Robin is a pretty good unit, probably my best lancer at the moment. I happened to get two so I’m thinking of sacrificing my spare one to Cordelia. By switching from Brave Lance + to Deft Harpoon + I’ll get +6 Atk/+5 Spd, plus an additional plus 2 to each stat when at 100%HP.
I’ve had no luck trying to get more Brave units. I’ve pulled 15 units and all I got was the new green armoured unit. It’s not bad but it’s not going to be a game changer in arena like the Brave units are.