Vex
Stubborn, with considerable damage and an incredibly strong shield creation ability, Vex possesses some of the most dominant traits. In fact, Vex’s presence has made the Mage composition extremely powerful without needing any pure tank units. Combined with the economic boost from the Yordles trait, Vex will make it incredibly easy for players to build their team. Therefore, it won’t be until Vex is heavily nerfed in terms of shield creation that the Mage composition will cease to dominate the meta.
However, in the upcoming mid-season update of Teamfight Tactics, Vex’s tanking ability will be significantly reduced. This is because Riot has added too many champions that can attack or reach the backline without needing the Assassin trait. The most obvious examples are Irelia and Tryndamere, who can dash straight to the backline, or Sivir, who can deal damage to multiple targets. This means that no matter how “tanky” Vex is, she won’t be able to sustain the entire team like before.
Seraphine
If you are someone who specializes in the Innovator composition, you will know that the strength of this team comp lies in its ability to heal and create shields continuously. Therefore, even with not too many tank units, they still last a long time in fights. Even with a fragile backline carry like Seraphine, thanks to the large and continuous healing, she can become extremely resilient. As a result, the Innovator team in Season 6 is an all-around composition that’s very difficult to counter.
However, as we move into Season 6.5, this strength has diminished significantly with Taric being removed and many new approaches to reaching the backline emerging. Taric’s removal leaves the Innovator team without a strong tank option in the mid-game, while the healing ability of the replacement, Senna, is not particularly impressive. As a consequence, the frontline of this composition can be taken down too quickly, even leaving Seraphine without enough time to heal, significantly reducing her value.
Kai’Sa
Once considered the strongest unit in “auto chess,” Kai’Sa has very little room to perform in Season 6.5, at least on the test server. The first reason lies in Riot maintaining the 4% appearance rate for 5-cost champions at level 8 in the upcoming Season 6.5, making it extremely difficult to roll for a 2-star Kai’Sa. This leads players to shift towards using 4-cost carries because they can upgrade them to 2 stars much more easily.
Additionally, with the emergence of many strong 2-3 cost champions like Tryndamere, Corki, and Syndra in Season 6.5, the reroll playstyle will become much stronger. Clearly, in a meta that does not support rolling for 3-star champions, using a 4-cost 2-star champion makes it very difficult to push to level 9 and use Kai’Sa as a carry. As a result, Kai’Sa has almost completely disappeared in the testing phase of Season 6.5.