In your companions page are in total 12 slots where you can place your companions, and 3 slots are available for the battlefield (each skill slot is activated by drawing the special sign - first skill is activated by drawing Z, second skill is activated by drawing an O and the last skill is activated by drawining the M sign). Only Story mode companions have a small background story.

If your companion dies when facing a group of enemies, he will auto revive after you do, or after you eliminate the group of enemies around.

As they reach max level cap, they cannot level up further. Max companion level is 70, same as your hero's. However, even when your companion unlocks all of their skills, they can level up and the in-game system will automatically add their base stats (amount based by each character). Each companion gives you one utility spell, and have other passive ones that unlock by his/her leveling up. To start, you have only one slot for companions, but you can unlock another two slots for 75 and 350 gems each. You can find three of them in the first act of the game, the other four of them can be bought for 500 gems each at the Store page. Companions are your only friends in the horrifying world of Mage and Minions.

Eternium best abilities for mage