Jemal
Adventurer
Siren doesn't have intimidate, that's for directly threatening people. I prefer leaving that roll to my attack bonus. 
Also their introduction had me thinking they worked indirectly in support of the aliens, not as a direct force.
I had planned to have Siren speaking down to them as someone in a position of authority would, insinuating that we worked for people whom they'd rather stay on the good side of.
I could see an argument that it should be a deception check to convince them that she works in a superior position to them. In that case her result would be 4 lower, for a 17.
I doubt this is going to work given the poor rolling..
If Siren gets another action before combat and realizes they're not convinced, she'll start singing her song.

Also their introduction had me thinking they worked indirectly in support of the aliens, not as a direct force.
I had planned to have Siren speaking down to them as someone in a position of authority would, insinuating that we worked for people whom they'd rather stay on the good side of.
I could see an argument that it should be a deception check to convince them that she works in a superior position to them. In that case her result would be 4 lower, for a 17.
I doubt this is going to work given the poor rolling..
If Siren gets another action before combat and realizes they're not convinced, she'll start singing her song.