I just did this guy last night.
I got totally tooled.
I think I might have bugged the game though. I was mostly darkside, even after I released (battled Vrook in the cave where he runs off). Then when I went outside, I lied and told the bounty hunters I would help them, and went and helped the town instead. After an extremely difficult battle, I win, and get to the part where the Administrator is thanking me. Vrook appears next to her. Anyway, I turn down the money, get a bunch of lightside points...then RIGHT after, I'm warped to the front area to fight Vrook. Why he appeared in the place with the administrator first is beyond me, but apparently he still wanted a piece, which was FANTASTIC after just having fought tooth and nail to win the base defense, and being already worn down and low on items.
So in my rather difficult position, I ended up loading a pre-battle save. I set deadly mines where the 2 invasion boss guys would be standing, and the other 3 in the room with Vrook. Then I set a bunch of frag mines where all the other mercenaries would be standing. Anyway, I then launched the battle, and they all nuked themselves on the mines, making finishing them all off a much more simple task. Kill one, run around corner out of sight, heal, repeat. On the very last guy, I loaded up on stims...Battle Stimulant, Hyper Alacrity, Stamina, Strength, and the Ark shielding. Worked over last guy quick, then went to the cutscene with the Administrator. Once I appeared in front of Vrook, he charged me and walked over a mine. I then spammed 'Kill' on him until he was half HP, triggering the next cutscene. Once that was done, I ran away, healed, ran around while hitting him with 'Kill' again until he was about 2/3 hp, then I ran him over the other 2 mines I had placed, and he died.
I must have tried him 20 times before I came up with this desperate plan to not only win the grueling battle beforehand, but then deal with him also.
The trouble is, I *think* since I switched, defended the base, was in the middle of the light/dark spectrum, and Vrook was standing there with the Administrator when she thanked me, I think the fact that I still had to fight him was either a bug, or a flaw in the games design.
I suppose someone could try to write it off as the cost of switching sides, but I don't think what happened was intended, especially considering it WAS NOT FUN in any way, shape or form, and was SO difficult that I nearly restarted the game entirely.
