Enfys Nest

It really depends on how you will mod and use her, but generally the best leader for her is Quira. However, like LordDirt says, she can be used just about anywhere on defense to deter certain counters. Using her with NS makes trying to best the NS with troopers more difficult, adding her to a BH team makes beating the BH with JTR or EP more difficult. Nest throws a wrench in a lot of teams because of her AOE daze and her mechanics in general mean you have to plan for her when fighting against her. However, in the end, she usually works best under Quira lead and if you want to get the most out of her that's generally going to be the best option, unless you need to shore up another team. I use her almost exclusively on offense under Quira with hermit Yoda to beat Padme teams, other than that I use her to solo weak teams.