I know you can unlock ToES by having one person in your raid group who has killed Empress.
This is my situation:
My guild has 2 raid groups, my group is stuck in HoF and the other group just killed Empress and Protectors. Now for their next raid day they need a sub for Tsulong. If one person from my raid group goes with them and they get a kill, would that person be able to reenter ToES the following week?
So without having killed Empress but they did kill one boss in ToES, is the raid unlocked? Or will they still be locked out of the raid?