It is an interesting combo. I would just repeat Death Urge unless I was short of PP's because the DC's are better. Phantasmal Killer is a better power but the advantage here that you get at least 1 attack as critical hit which will probably do more than the average damage of 3d6 if the target.I'd at least take Death Urge, but I have to think carefully about Deja Vu. DC would be at least 16 for DU and only DC 16 for DV. If I'm going to use the same amount of PP's, I'm going to use the higher power because the immunities are easier against lower level powers.
At 11th level, the DC is at least 18 and with DU works for two rounds. I applaud the thinking but upon reflection, DV falls short as a combo with this power.