Mostly used heroes are Gale,Garrick,Jasmine,Drago,Leon,Riley,Dokras,Arachna
I suggest u to focus on these but if u have time dont neglect these heroes-Ethera,Ulfang,Musashi(for raids and HoL),Ariel,Gizmo,Serafine,Osiris,Tholin,Tanya..
Keep at least 10 fully skilled and levelled heroes for mobility(Arena,Crucible and raids) when u reach 80 u ll have a lot of time to focus on other heroes cuz it gets harder to progress

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