Just defeated the emperor the other day as a level 48 watchman spec sentinel. I hadn't geared T7 since the beginning of the game (he died within 1-2 seconds); didn't use the pillar trick either. Just interrupted his Force Blasts, didn't pay any attention to the clones. I tried to keep Force Leap cooled down for when he generated the clones, that way you can still deal DPS to the correct target without losing time/HP. Popped 'Guarded by the Force' when my health got very low, followed by an immediate medpac. It was a close finish, but is doable if you pay close attention to cooldowns, time interrupts appropriately, and follow a good skill rotation. This is a tough encounter, as it should be. It took me three tries - the first two I thought there was no way I could win without gearing up T7 (or leveling to 50). However, even if you properly gear T7 I hear he still gets killed very quickly. I wasted 'call on the force' during my first encounter; ended up defeating him without it.

I, like others, was surprised that I couldn't bring Doc to the T7 only fight at the end of the game. I hadn't geared T7 up at all since the beginning of the game and used Kira until I got Doc. Thus, T7 gets killed in literally 1-2 seconds by the boss. That said, I managed to beat the boss (as level 48 watchman) in about three tries. I ended up doing it without using 'call on the force', although it took a medpac and 'Guarded by the Force' about midway through the fight. Doc is by far the best suited companion for a watchman spec'ed sentinel. I highly suggest keeping him geared up, the other companions are just a bonus.

I just beat Valis as a level 24 Sentinel. I originally got rocked when I attempted to face him at level 23, but having Stasis at level 24 makes all the difference. As others have said, time force kicks and force leaps as well as possible. I went ahead and used Call on the Force right from the get go. Also, putting the crates behind you is invaluable in this fight. If you've got any commendations from other planets built up, its a good time to use them for upgrades or just get roll boxes and sell them for creds. I used a might stim and a field med kit for this one. I had about 50% of my HP left at the end of the fight, although Kira died like 75% of the way through.