I threw it into the middle of the room, dispelling part of the DarkCloud. My Avenger and the Swordmage in our party then kept pulling/pushing/sliding/teleporting our targets back into that zone of light.
Drow dangerous again! Another reason to love 4E.
But...
As noted, to hit with a poison on a weapon takes a second attack vs. fort. This is spelled out in the DMG (including for drow poison).
Still, I have to credit your dm for giving you hell.![]()
Yes, they are very tough. Fighting them would be a great time to use leader powers that grant extra saves since only the fail at the end of your turn results in bad effects.
Unless you were a very unlucky Warden (fail 1st time at beginning of turn with Font of Life, fail at end of turn with regular save)