Divine
To put it bluntly, the Divine class has become increasingly dominant in season 6.5 after receiving indirect buffs from Riot. The most noticeable change is that activating the 3 Divine trait is now much easier with two 3-cost units from this class, Senna and Gnar. This means that at level 8, you can reach the 3 Divine trait (with Seraphine) and significantly buff a carry. A prime example is Irelia, who is currently incredibly strong in the meta.
Another factor that makes the Divine class so powerful when combined with Irelia is that Gnar also possesses the Assault trait. Therefore, having just these two units on the board means Irelia will inherently have the potential to deal tremendous damage, which only increases over time as higher Divine thresholds are activated. Perhaps Riot Games needs to nerf the stats of the Divine thresholds slightly, especially the first two activations, to balance their power.
Challenger
In fact, the Challenger effect itself is not overly strong since it requires your champions to defeat opponents to gain increased attack speed. However, the strength of the Challenger class lies in having a plethora of powerful carries spread throughout the game, making this composition have very few weaknesses. You can even reroll with the Challenger team early on to push Warwick to 3 stars, and that unit will “carry the team” all the way to the late game.
Therefore, it would be most reasonable for Riot Games to reduce the damage output of 2-3 cost Challenger units like Warwick, Quinn, or Tryndamere. Not to mention, Warwick’s excessive healing ability also needs some adjustment for better balance. Additionally, the extra attack speed provided at the 6 Challenger threshold should be slightly reduced so that this team’s snowballing capability in fights is not as overwhelming as it currently is.
Innovator
Even though it has been repeatedly nerfed, the Innovator class remains incredibly strong, evidenced by the numerous variations that are at the top of the Teamfight Tactics meta. You can combine Innovators with Jhin, Twitch, or Irelia as carries depending on the match situation. In even luckier cases, players can push Seraphine or Jayce to be carries. In summary, the Innovator class is currently too powerful and can perform well in any game.
Of course, a strong composition like this needs to be weakened. I think Riot should add a bit of energy lock time for the Tech Bear or make the unit’s skill cooldown slightly longer. The Tech Bear being able to use its skill too frequently in fights grants the composition a tremendous amount of attack stats. Adding delay time when casting skills will make the Tech Bear much easier to counter than it currently is.