SMITE

This isn't really a solution but more of a clarification. The description for this is a little misleading. You have to be only god alive in the game. It's confusing because it can be taken as be the only god left alive on your team, but that's not true. Out of the 10 people in the game, you have to be the only one alive and it's kind of luck based. Conquest or Assault would be better for this because of the long respawn times. Completely skip Arena because of the short respawn times.

To earn Last Man Standing you must be the last god alive in a game of Conquest, Arena, Assault, or Clash.

You can earn this in the new Arena bonus round.

It's a fight to the death in a circle surrounded by lava. So hope that your teammates die and that you can kill the rest of the enemy team and you got it.
It may be hard to pull off but it may happen on accident anyways, and it's harder to do it legit in any other way.

Recommendations: Xing Tian's Ultimate, Anhur's 1 or Tyr's Attack Stance Carry move. (If you are really good with another god, just use them, of course.) Also, Purification and Sanctuary are must haves. Enemies will also have them though so the "Recommended" gods probably won't work out too well if you don't know how to use them.

Pro: No Respawns
Con: Only One Try a Game

Best of Luck!
(Bonus round no longer exists)

There is a game mode going on right now (12/27/22) called Till Death and it’s is a 2v2 mode on Assault. This is where I finally nabbed this achievement since you only have to worry about 3 other people being eliminated rather than 9. If you are struggling try this game mode as I got it on my first round on this game type. I do not know how long it will be up or when the game mode rotates but I can confirm this achievement is possible in it.