User blog comment:Linathan/Squad Spotlight: Essential Squad Compositions/@comment-26347196-20151211160652

Also, can I tell you how much roles Charla filled up in an essential squad?

Her leader skill fills the BB fill role (and perhaps survivability)

Her BB fills the role of BB booster and gradual booster, HoT buffer, healer and anti-debuffer

Her SBB fills the role of crit and spark buffer (greatly, even)

Pair her up with Gazia, who boost BB Atk, Atk and Def, and is a mitigator, the two literally just covered almost everything.