I still have not been able to think of someone for Seriphyn. So, renegade Shepard he shall be.
"I don't have time to justify myself to your viewers, I have a Federation to save, excuse me"
Now to send a mail to Mark Meer and ask him to do some voiceovers
Also, without the accent or skin colour, Seriphyn probably has the one-liner quirks of Arnold Schwarznegger etc. especially when shooting people...so that is his stand-in for now