Story

Hit is an incredibly powerful assassin from Universe 6, where he is known as the living legend of the underworld. He's also over 1,000 years old!
He agrees to compete in the martial arts tournament held between Universes 6 and 7 as the ace of his universe's team, but only on the condition that if they win, he gets to keep God of Destruction Champa's Cube-Type Spaceship.

(Dragon Ball Super Chapter 7)

During the tournament, Universe 6's warriors are knocked out one by one until only Hit is left to face down Universe 7's remaining members, starting with Vegeta.
Using his Time Skip ability that allows him to momentarily freeze time and unleash high speed strikes, Hit is able to evade and counter all of Vegeta's attacks.
Even after Vegeta transforms into his Super Saiyan God Super Saiyan form, he suffers a convincing defeat at the hands of the legendary assassin.

(Dragon Ball Super Chapter 12)

Goku is next to step into the ring with Hit, who is astonished when the Saiyan is able to counter his Time Skip by predicting what attack he's going to use a fraction of a second before he activates the technique!

(Dragon Ball Super Chapter 13)

Hit then tries to plan his own moves one step further ahead of his opponent's predictions but is foiled again when Goku transforms into Super Saiyan God, where the sheer difference in power between them causes the amount of time Goku can be affected by Time Skip to shrink!

(Dragon Ball Super Chapter 13)

Left with no other option than to close the gap in power between him and Goku, Hit unleashes his full power at last, knowing that his body won't be able to maintain such high output for long.
In an attempt to close out the match, he bets everything on one final Time Skip, but Goku sees it coming and counters by transforming into Super Saiyan God Super Saiyan at the exact moment Hit attacks, giving him enough power to dodge just in time!

(Dragon Ball Super Chapter 13)

Goku then fires a Kamehameha that Hit manages to barely avoid, causing the assassin to acknowledge his strength. However, Goku suddenly exits the ring voluntarily and disqualifies himself, saying, "I just can't afford to lose this chance to see our best guy fight," referring to Universe 7's final member, Monaka.
Monaka steps into the ring to face Hit in the final bout, but it turns out that when Beerus told the other Universe 7 members that Monaka is the most powerful fighter in their universe, it was just a lie to get them fired up and make them fight harder! In reality, Monaka is a completely normal person with no fighting ability of note whatsoever!
Realizing this, and knowing that Goku was the true victor of their match earlier, Hit takes a dive after being struck by a feeble punch from Monaka and loses by ring-out, making Team Universe 7 the victors of the tournament.

(Dragon Ball Super Chapter 13)

First Appearance

"Dragon Ball Super" Chapter 7

Techniques

Time Skip
A technique where the user stops time for around one-tenth of a second and unleashes high-speed attacks in the interim.

Trivia

For around a fraction of a second before he activates Time Skip, Hit can't actually change what move he's going to use. That's why he keeps his hands in his pockets—so that his opponents have a harder time figuring out what he's going to do next! It's also the reason he keeps his legs concealed under that long coat.

(Dragon Ball Super Chapter 9)

→Preview: Next week's character is someone who beat Hit's Time Skip!

*All comic images are from the Japanese version.