Pain Offering targeting

Can someone please explain to me how Pain Offering decides which minion is offered? It now targets my Arsonist 9 out of 10 times. This is my strongest minion. How can I avoid this without using the manual cursor?

Feedback: I play with a controller. I would like pain offering to choose a skeletal warrior automatically. Or my lowest level minion or te minion that is the lowest in skill menu.

Or does it choose the highest level minion because it gives a higher buff?