Terraria, but I play as Mage-class only!

You say, as you have two birds on your head

Ye?

The birds are from the summoner class

Still uses mana.

The mage class uses weapons that drain mana, and require aiming to use it properly, while summoner class weapons summon minions to fight for you, and are usually used once per life

Hmmm fair.

So yeah

Summons are not part of the Mage class

They're their own class