Varar is so bad. Almost every situation where she can OTK, Duralume can do it just as well and do it easier, and in the situations where Varar is going to get an OTK Duralume can't, just making Dugares to boost Duralume will do even better. And as an interruption Zebufera is far better.
But I'm still dedicating an ED slot to her, and still will go through the extra motions required to OTK with her when the opportunity arises.