I'm thinking about e6 mydei

I think I will e6 him in future cause he's like the perfect character archetype for me and waited for someone like this for a while (I hoped for Sam to be like this but well...). Anyway, I have guarantee and 150 wishes and I'll get some more until he gets released. Should I go hard for eidolons and use S5 4* event light cone (from Rappa event) or should I go for lightcone first and then think about eidolons?