Last month, Riot Games announced on video its plans for the rest of the year for League of Legends but also for Teamfight Tactics, including the addition of new champions, galaxies and small legends to Set 3.
A Chinese player managed to extract files from the client after updating patch 10.10, and apparently discovered the next champions to join the Convergence.
Nidalee, Gnar, Janna, Morgana, and Kog'Maw might indeed join the fight!
Nidalee and Gnar are shown in their intergalactic skin, just like Annie, Rumble, and Fizz — meaning we can safely assume that they would join the Mech Pilots family. It would also signify that the Trait might be changed by the addition of a new five units threshold.
However, the return of Nidalee and Gnar might also announce the return of Set 1's Shapeshifters...
Janna will certainly join the Star Guardians, but it remains to be seen which one of her spells will be used — but we can imagine that it won't be her R once again.
With this skin, it's hard to predict where Morgana will be placed. It might presage the addition of new origins... One could however imagine her becoming a Valkyrie to replace Kayle — considered too strong by many players.
Kog'Maw, present in its basic skin but also with its Battlecast Kog'Maw skin. It could very well have originated from that of the Void and unlock synergies with 2 and 4 units.
All the information above are to be taken cautiously, Riot Games didn't confirm anything about it yet.