The Crystal Scar and Twisted Treeline are very unlikely to ever come back in League of Legends according to Riot Games.
Crystal Scar or Dominion game mode was released in League of Legends back in 2012. The mode was played on a unique map and had faster gameplay. However, after being in the game for years, the mode gradually became “dead”. And according to Riot, only 0.5 percent of League players played the mode actively where most of them were bots.
Therefore due to lack of popularity Riot had to permanently retire Dominion and the Crystal Scar mode in 2016.
On the other hand, Twisted Treeline, the 3v3 mode that was in the game for 10 years, was shut down on Nov 19, 2019. On Riot’s defense, the game mode didn’t “meet today’s current quality bar and player needs.” Hence they had to remove the mode entirely.
However, both game modes did have some loyal players and after years of their removal players are again asking Riot if The Crystal Scar and Twisted Treeline are coming back to League of Legends or not.
And replying to the question, Riot Reinboom said Crystal Scar and Twisted Treeline are “very unlikely to come back.”
“The Crystal Scar and Twisted Treeline for that matter were built for an old environment renderer that’s no longer around. To return those maps, they will need to be rebuilt entirely,” Riot Reinboom added. “The only map so far that was built for the old renderer that was then rebuilt as-is for the new renderer has been Howling Abyss.”
Riot Reinboom also mentioned that old renderers like Crystal Scar and Twisted Treeline can’t come back since “utilizing it prevented League from adopting newer versions of DirectX.”