As Riot Games has announced, the “massive” mid-season update for Teamfight Tactics will change almost the entire gameplay from meta to playstyle. Although this update has not yet appeared, you can still familiarize yourself with some old compositions that maintain their strength after the update. In fact, with the mid-season changes, these compositions may become even more powerful.
Here is a list of those compositions:
Gadgeteen – Irelia Will Have a Valuable Ally Soon

Even in the current meta, Gadgeteen is still a very powerful composition with the main carries being Irelia and Ekko. In the upcoming update, the only change that will impact this composition is the disappearance of Miss Fortune, but after all, Miss Fortune and Ekko have always been like oil and water, so Gadgeteen doesn’t have too much to worry about.
You should get familiar with this composition early, as Irelia’s devastating stabs may become even stronger in the mid-season update. With the introduction of Riven (Blademaster + Chrono), Irelia will benefit to some extent, and with Vayne added, the carry role in the Gadgeteen composition will undergo significant changes.

Gunner Brawler – The Definition of “Mage with Guns”

If you’re not yet adept at using this composition, you should get familiar with it right away because it’s already quite strong and may become even stronger soon. It can be said that the disappearance of Miss Fortune has the biggest impact on this composition. However, the mid-season update not only removes many champions but also brings in many new ones.

Specifically, the Gunner Brawler composition can retain the strength of the old framework except for Miss Fortune. Additionally, the Gunner lineup also includes a new carry, Kog’Maw (whose ability requires only 30 energy, increases attack speed by 90%, and deals damage based on a percentage of the target’s maximum health). Additionally, the Brawler lineup has Illaoi and Gnar, significantly increasing its tankiness.

Finally, the game-changer in the meta will be Janna – who turns all the damage from this composition into magic damage. At that point, these “mages with guns” will be able to turn the tables against all armored players; if done skillfully, you can remove Janna to regain physical damage when facing players with Mystics – the mixed damage of the new Gunner is very unpredictable.
Mage Gangplank – The Return of Mages

Although the Mage composition is not strong in the current meta, combining it with the “national champion Gangplank” tells a different story. With just one combo, Gangplank can wipe out the enemy team thanks to the massive damage from items and 6 Mages.
The reason you should get familiar with this composition early is that it will help you master the playstyle of the Mage and Gangplank-centric team, which will become exponentially stronger post-update due to new items and champions like:

With the power of 4 Mages, a Cannon Barrage from Gangplank may slightly reduce its effectiveness compared to 6 Mages. However, with the true damage provided by the Celestial Guardians behind, “Syndra and her friends” will finish off any lingering targets after Gangplank’s ability.
If you’re lucky, you might get a Celestial Guardian’s Blessing and throw it to Gangplank, at which point a true damage Cannon Barrage will leave your opponents stunned for 5 seconds.
Cosmic Darius – One Step Back, Two Steps Forward

You could say Darius still brings a very “satisfying” feeling to players, as every strike can yield a kill or gold (sometimes yes, sometimes no). But fundamentally, this composition is very promising, not only strong at the start, but in the late game, if Gangplank and Graves activate Scoundrel to “hack items”, it can be fantastic. Therefore, in the current meta, getting accustomed to this composition’s playstyle is completely beneficial.

As for the mid-season update, the Cosmic Darius composition will lose Kassadin but gain a super strong Guardian, Urgot, along with a secondary carry, Kog’Maw (if you can hack items from Scoundrel, it should go to Kog’Maw). Kog’Maw could become the primary source of damage (even without items) in the mid-game if the composition lacks damage.

The above are the old compositions that can maintain or significantly increase their strength through the addition of a few new names. However, with 2 new Traits and many other individual champions, many new and interesting compositions will emerge, and the compositions above can help you gradually get acquainted while exploring these new lineups.