Douluo Dalu: I Summoned Mu Ningxue, and She Insists on Becoming My Master

I transmigrated into Douluo Dalu and summoned Mu Ningxue from the start, but why does she insist on being my master?

And what is this about her being cold on the outside but warm on the inside?

I summoned Queen Medusa! Same personality!

…

Mu Ningxue: “Be a good disciple. Your Martial Soul is a bit disappointing~”

Queen Medusa: “Be a good disciple. Your Martial Soul is even more suited to my attributes, Master~”

Bibi Dong: “Hmph! Shameless old women, every one of you. Unlike Dong'er, I only know how to dote on my dear brother~”

Xiao Ran: “Why is Mu Ningxue acting so weird? Has Queen Medusa caught it too?”