You have the best heroes! But I'd personally use Blue King instead of Blue Lillia because he imposes more threat (Petrify, High damage Ultimate). His recovery skill can readily be used at rank 1 to purify LV Meli, which is crucial in removing debuffs when your team goes 2nd. For sub unit, I'd go for Green Merlin or Red King. I still use my Blue Lillia in PVE with Red Howzer and Blue Demon Meliodas.