Everyone is aware that over the past few months the Uni-power has been bonding with various heroes and copying their abilities; adding their powers to it's own. So, in addition to the power it already possessed, it added the powers of the Invisible Woman, X-23, Daredevil, Hulk, Gladiator, and the Silver Surfer to it's own. (It looks like Marvel is trying to set up something MAJOR for the Enigma Force.)
Now take Sentry, add the powers of the Uni-power that we already know of, then add the powers of the people I just listed too. Now that's a formidable opponent.
In the end, Sentry would still go down though. Don't get me wrong, I'm an avid Sentry fan, and a pretty good Captain Universe fan, and I'm not really a Lantern fan; but even I must admit that that's just too many Lanterns to take. He'd have better luck againt Ion or Parallax.