I need a little help on my champion choice. At the moment, I have a couple of Epic champions level 1 (just bought) and the ones I was using before 

Here it comes 

Galek: Level 26 (with potential level 40)  4 stars 

Alika: Attack, Barbarian, Epic, 4 stars level 1

Lich: Attack, Undead, Epic, 4 stars level 1 

Luria: Attack, Dark Elf, 4 stars level 1

Warpriest: Support, 3 stars, Level 30 on max

Berserker: Attack, Barbarian, 3 stars level 30 max

Cataphract: Support, Banner lords, 3 stars level 30 max 

Elder: Defense, Barbarian, Level 16

Marked: Support, Barbarian, Level 10

Skirmisher level 1

Gladiator level 1

Skullsworn level 1

Bone Knight Level 1

What would you recommend to upgrade or use to upgrade the other champions?