I've enjoyed Power for 5 whole seasons, but if episode 1 of season 6 is a precursor to what is to come... than frankly, the show is unfortunately starting to run out of steam.
I think this show just suffers from a fundamental eventuality with all gangster dramas... you can only kill-off so many characters, before you begin to erode the continuity of the show; and, I'll just leave it at that... to avoid any spoilers to those who haven't watched the end of season 5, or the beginning of season 6.
Also, the suspension of disbelief is getting to be way over the top, between how the characters interact... which is a function of writing. The actors aren't necessarily over-acting -- even though they oftentimes appear to be -- but, rather, the over-the-top writing is starting to place the cast in predicaments that just aren't at all plausible. Which isn't entirely unexpected. It's got to be tough work to piece together a plot when there's little left to put together.
I was also disappointed that there were no new characters introduced; (on the protagonist side) but, I assume that there will have to be - to keep this show going, because, with the present cast, it's just getting a bit stale.
The lead will need a new love interest, and another high value foil. Conversely, nearly all of the present characters are becoming unlikeable and hateful, and unless something or someone new is brought in to spark that original feeling - of a sympathetic figure that just got caught up in the life, trying to protect what's his... than, we're just down to going through the motions, watching everyone scheming to burn everyone and everything else to the ground.
Frankly, I'm not too excited to see a show devolve into that. I liked it better when - despite all of the warring and back-stabbing- there was always something left to appreciate and long for... with characters that would reminisce about their younger days.
I'll give the show a few more episodes to see if they can breathe new life into it. But, as of now, this show seems like a jeweler that's fresh out of gems.