Need help dealing with Sidhe Lords

[Illuminated One]

Hmm, I find empowering anyone is always the worst choice (sure if that's your only way to get into a path, but never just for a little more combat efficiency).

I suppose you need the Astral1 (?) for buffs - in that case some of your astral mages should be able to cast Luck and Body Ethereal on him if you put them in the same square.

Also I don't know if the Shroud is such a good idea, since it has no good prot. When engaged in melee the Sidhe will strike back.
If you don't have air for lightning res stuff the prot issue can be fixed by spells (Iron Warriors) or Boots of Stone.