These champions below are set to receive massive buffs from Riot in the upcoming patch 13.9.
Kayle
Despite her immense potential, Kayle hasn't been getting much love from players in League of Legends. One of the main reasons is her heavy reliance on the Divine Judgment core to deal effective damage. Without this upgrade, Kayle seems quite fragile even when pushed to 3-star with full items.

Therefore, in the upcoming patch 13.9, Riot Games will significantly strengthen Kayle's interaction with items. Specifically, the interaction coefficient with attack power from Kayle's abilities will increase from 155% to 175% in the next version. This change allows Kayle to still deal effective damage without relying too much on the Hero's Core.
Camille
With the Cybernetics trait weakened, Camille has also felt its impact significantly. This champion is now less utilized compared to before. Camille will now play the role of a surprise champion for opponents rather than a staple pick for every match.

On Riot's end, they want Camille to be used more, so in the upcoming patch 13.9 of Teamfight Tactics, this character will receive significant buffs. Firstly, Camille's skill damage will be greatly increased. Furthermore, the crowd control duration from her abilities will also be increased to 2 seconds at 3-star level. These promise to be necessary buffs for Camille to return to the meta.
Jax
With his strength significantly reduced, Jax is no longer the overly powerful staple he once was. Additionally, Warwick's appearance also makes players prioritize pushing Warwick as the main frontline rather than Jax. However, this could change in patch 13.9 as Riot Games decides to increase Jax's strength.

Specifically, the additional damage on Jax's third strike will be increased at 1 and 2-star levels. This helps Jax to deal more damage at the beginning and middle of the match. This damage will become substantial if Jax owns the Guardian Angel and items that increase attack speed. It's highly likely that the magical Jax playstyle will return in the next patch.
Conclusion
With significant power increases in patch 13.9, Kayle, Camille, and Jax are poised to be noteworthy champions in the future. Moreover, these champions could even bring back the reroll meta in the upcoming patch.