I don't think a movie with dinosaurs can get any more epic than that

Who do you guys/gals think would win? The Indomitable King or the Tyrant Lizard King?

At the end of the movie, Owen re-establishes his bond with the raptors before the Indominus reappears. The raptors attack the Indominus, but three of the four are killed. Claire lures the park's Tyrannosaurus rex into a battle with the Indominus. The two dinosaurs fight, with the Indominus gaining the upper hand until Blue, the lone surviving raptor, joins the battle. Overwhelmed, the Indominus is backed up to the lagoon, where the Mosasaurus leaps out and drags it underwater. The T. rex retreats, followed by Blue, who turns to acknowledge Owen before leaving. (taken from wikipedia)

It has been confirmed that this T-Rex is the same as the one in the first movie.

I do not think the T-Rex befriended Blue.

I think that the T-Rex is afraid of Raptors. Seeing how well Blue fought the Indominus Rex, and being wounded in the first movie, around the neck by raptors, I would say that Rexy came very close to dying, and was since very carefull around them.

Let's not forget he/she(?) is also very old. (at least 22 years). Histologic analysis of Tyrannosaurus rex say that aprox 30 years of age may have been close to the maximum for the species.

They are also very territorial, seeing the Indominus as a threat, not Blue, thus ignoring it.

After fighting the Indominus, coming very close to losing, fighting a very agile raptor would have been a death sentence.

TL;DR: Rexy was afraid of Blue.

Feel free to chime in.

Rexy was practically throwing the Indom around the whole entire fight. While true, the Indom was winning in the beginning, Rexy got her footing and had a solid almost minute of squaring up with the Indom, who was getting clapped. And before you mention Blue "helping", she was barely at all. Owen could've even distracted the Indom from a distance, and we would still have the same result as what happened in the movie. I mean Rexy was REALLY slamming the Indom around, and let's all remember how the Indom is stronger than spino (it's not a debate at this point). You also gotta remember how Rexy took a hell of a lot of slashes from Indom, I mean at the end of the fight the amount of wounds on her is crazy. And judging by the fact that Spino has trouble with an inexperienced, juvenile bull(who only won bc he let the Spino grab his neck), JW rexy would no doubt win. Not to mention JW Rexy had visible ribs, not like she's in her prime or anything. Once again, I'm not trying to upset anyone, feel free to give your own thoughts. I do ask that you guys please be respectful tho, as everyone is entitled to their own option and this is pure speculation

As I’ve mentioned before, the fight starts in Rexy’s favor. When they were chomping at eachother, Rexy had the upper hand, whipping the Indominous around. The tides only turned when Indo started clawing Rexy in the face.

Later, with the help of a single raptor; Rexy was able to completely outmatch the Indominous, throwing it around easily.