firefighter tristana skin

Long ago it used to happen right now. They have long since stopped most of those un-vaultings as they can be gotten through Chests, mystery gifts, ect (albeit random) but that's how Riot does it now. The only other time she was available directly was when they updated Tristana and again when they updated her splashes. So, there's really no way right now that it has been available directly.

I think Firefighter Trist is one of those skins to never come out of the vault for purchase again, not too sure on that tho.

The only way you can get her otherwise is through hextech loot.

boxes, orbs, anything that gives skin shards ((if it has higher chance of Legacy skins that’s better)).

A friend of my was able to get it through the your shop.

Keep in mind despite it being a "legendary" skin it has no voice over change, only way I know to get is getting very lucky with basically the loot boxes.