As Dragon Ball Z's most iconic villain, Frieza's resurgence has had its ups and downs in Dragon Ball Super, but it's difficult to imagine Universe Seven could have won the Tournament of Power without him. At first glance, Frieza seems like the worst possible person to help save the universe, considering the tyrant only ever looks out for himself.
Surprisingly, as his performance in the tournament demonstrates, if Frieza decides the best course of action to serve his own self-interest is being a team player, it's a role he will play to perfection.
It initially appears Frieza is up to no good as usual when he approaches Frost, his Universe Six counterpart, and suggests forming an alliance. He encourages his naïve new partner to go all out from the start, and Frost eliminates several weak fighters from the tournament -- allowing Universe Seven to save its collective energy. For Frieza, so used to power and well-versed in controlling people, his manipulation of Frost not only clears the field a bit but keeps the otherwise dangerous fighter preoccupied while exhausting his strength.
In addition to his clever scheming, Frieza also displays an impressive aptitude for cooperation. When Gohan is being overwhelmed by a master of Instant Transmission from Universe Two, Frieza intervenes to prevent the half-Saiyan from being eliminated. Easily dispatching the fighter, Frieza not only saved a teammate but also removed a troublesome opponent from the battlefield.
It seems only Goku and Gohan truly understand Frieza will help them because it’s in his best interest to do so. This is why it's fortunate that Gohan was the one nearby when Frost reappeared, as he recognizes Frieza's apparent betrayal and alliance is no more than a ruse. With an impressive acting performance, Frieza "defeats" Gohan, causing Frost to let his guard down, allowing Frieza to swiftly dispose of the Universe Six fighter instead.
Considering he once almost lost his life to Goku's Spirit Bomb, it was all the more surprising and delightful to see Frieza gladly donate his energy to it in Dragon Ball Super -- something even Vegeta refused to do. After the Spirit Bomb is a complete dud that Jiren effortlessly flicks back before swatting Ultra Instinct Goku across the ring like an orange volleyball, Frieza finds the exhausted Saiyan and shares some energy with him. He alludes to repaying the debt from Goku sharing his energy back on Namek and explains that he needs Goku to keep fighting if Universe Seven is to have any chance at winning.
Frieza later saves Goku again by kicking him back in bounds after the Saiyan was sent hurtling out of the ring by Anilaza, a gigantic monster fused from several Universe Three fighters. He even participates in a signature Dragon Ball energy-beam battle that eliminates Universe Three entirely. As the Tournament of Power rolls on, he employs genuine teamwork with Gohan to defeat Dyspo, the speedster of Universe 11. However, Frieza was unable to prevent him from being ringed out this time as the Saiyan's sacrifice was necessary to eliminate Dyspo.
The galactic tyrant was also pivotal to the final showdown with Jiren, saving Goku from elimination yet again while cooperating with Android 17 to hold their opponent off until Goku could get back on his feet. After being reassured Goku would fulfill his promise if Universe Seven wins, Frieza completely dedicates himself to victory, fighting side by side with his least favorite Saiyan. He even attempts to drag Jiren out of bounds at the cost of getting himself eliminated. Goku and Frieza ultimately unite their power and succeed in knocking Jiren from the ring, securing the win for Universe Seven.
In line with his character throughout Dragon Ball Z and Super, Frieza employed many cruel, sneaky and dishonorable tactics during the Tournament of Power. However, there was a degree of practicality behind his actions. After all, the objective is to knock people from the ring, and with the entire universe on the line, it shouldn't matter if he pounces on an exhausted fighter and tosses them over the side. The tournament was always going to get messy, so Frieza was the perfect addition to the team, not only willing to do the dirty work but preferring it.