Board Thread:Questions and Answers/@comment-26710740-20150716162112/@comment-26297531-20150716202427

Tips for squad building: get units with different types of buffs in your squad, as no 2 same buff can stack. Generally you want to have buffs like these in the following importance / activation order : BC/HC, Element, Crit, Spark, Atk, BB regen, BB regen on hit, Def, HP regen. So just look through your units yourself and determine how to get the most number of the above buffs with the units you have.

Also, generally having 1 mitigator (and maybe 1 healer) will be good for harder content.

Some of your note-worthy units:

1) Mitigators : Aaron, Elimo (healer too), Copra. These are all 7 stars possible units that are quite meta now. Narza is good 6 stars mitigator for his sbb buff since you currently lack that kinda buff.

2) Anti-debuff : Kanon (great defensive tank lead too), Ivris (very useful healer for her ubb), Andaria (offensive anti-debuffer with bb regen buff, getting her 7 stars in time to come too).

3) Atk buffer : Vargas (only in 7 stars form, which is far away for you to consider if you just started out), Zergel, Kuda (also buffs crit rate, which has higher damage multiplier than just Atk)

4) Ignore Def (very useful for Metal Parades) : Vanberk (also has crit buff, but he's less recommended due to low BC drop check).

Status inflictor like Balgran also has specialised use in certain content. Do your own research around the wikia for those content.

Finally, Snow Queen Eva seems like your best candidate for lead for now. She has nice boost in BB fill rate and BB regen on hit leader skills. Her sbb also grants you crit buff.