Why is the event's main character never available in the 3-4 star arena?

Ambs13

Like when the month's main character is Thanos but the 3-4 star character is Howard the Duck

mum_m2

so you're looking at two different types of arena. one is a featured arena. and the other is the basic. You won't see the featured champion in the basic arena for a while, but this is a chance for the early adopters to grind it out for the champ they want.