Your weapon attacks are very precise and deal a surprisingly large amount of damage. Barring if he's being healed, if you focus your attacks on Drogoz, you should be able to take him down within a single clip.
When Lex is attacking you, try to keep your Illusions between you and him. None of his basic abilities can shoot through multiple targets, his In Pursuit will be forced to target your Illusion instead of you, and you'll receive constant healing.
If you can land a Pyre Strike on Talus when he's approaching half health, you can keep him from manually returning to his Rune of Travel and give you and your team time to finish him off.