What do I use these blue tier one alpha catalysts on

I'm new to the game and haven't found a use for them yet I have two

Comments

Leveling up your 4* champions.

Leveling up your 4* champions

Ranking up 4*s passed rank 2 (and above).

Can I star the 3* champions

Can I star the 3* champions

No. A 3 star champ will never be more than a 3 star champ, a 4* champ will never be more than a 4 star champ, and so on....

They're used to rank up members of the Blue man group