Since we have:
A lost prince of a massacre on his kingdom
Girl born with a lost magic
The grim reaper
God blood infused human
What are the chances another anomaly joins us? Maybe a spirit weapon user who doesn’t need a god blessed artifact to summon spirit weapons.
The only one that is an anomaly is Iris
We got four in our gang. If we follow the standard five man band
We got us, the hero
The gentle brawn: Morden
The smart guy: Neviro
And the girl: Iris
There is a chance the new addition to our team would be another girl with a more feminine attitude than Iris.
If I were to predict it would be someone with a Spirit artifact that held significant value