Originally Posted by smr

Justicia and Apple for their overall abilities and multi attacks, Chocolate Cosmos and Lantana for healing node support, Mirabilis for overall performance as well as being a fully unlocked knight that most players own that greatly increases the effect of her counterattack ability

Don't forget Cyrtanthus, she has the same "1.2x Battle Skill activation rate for all Squad members based on Affection" ability as Justica and Apple.
Her other ability is not as good since it only works on raid bosses but the Battle Skill activation rate manipulation is why the other two are so good.