Physical Traits

Strength

Kylo Ren holds lieutenant Mitaka up with one hand.

“Reaching out, a black-gloved hand clutched the startled lieutenant and pulled him violently forward. That metallic visage was now close, closer than Mitaka had ever been to it. As the officer struggled to breathe in that remorseless grasp, Kylo Ren’s voice took on a timbre lower and more menacing than any the lieutenant had ever heard.”

--Taken from The Force Awakens novelization

Kylo Ren is considered stronger as Rey.

“To an observer at a distance, it would have appeared as if a series of small explosions was going off in the depths of the forest. Blow after blow landed as lightsaber struck against lightsaber. Though Ren was bigger and stronger than Rey, their struggle had nothing to do with physical size.”

--Taken from The Force Awakens novelization

Speed & Agility

Kylo is said to have immense reflexes.

--Taken from The Force Awakens The Visual Dictionary

Finn and Rey can’t outrun an injured Kylo Ren.

Finn kept pulling them forward. Kylo Ren was surely close behind them. The red flash of his lightsaber caught Rey’s eye. Rey and Finn stopped for a moment and looked at each other. Silently, they agreed that they couldn’t outrun him.

--Taken from Rey’s story

Kylo Ren is fast enough to easily deflect the blaster bolts Rey shoots at him.

Kylo easily deflected both bolts. With a terrifying confidence, he walked toward her. Rey fired shot after shot, but Kylo deflected every blast.

--Taken from Rey’s story

Durability & Pain Tolerance

Kylo Ren keeps on fighting after being mentally hindered to the point the fell to his knees in shock and being hit by Chewbacca’s bowcaster.

“Stunned by his own action, Kylo Ren fell to this knees. Following through on the act ought to have made him stronger, a part of him believed. Instead, he found himself weakened.”

--Taken from The Force Awakens novelization

“Amid the rising bedlam and confusion, Kylo Ren struggled to stand.”

--Taken from The Force Awakens novelization