Immortals Fenyx Rising

During a mission for Athena called “Go Do Hero Things!” you will come to a section where you must restore a statue of Achilles. After restoring the statue you will have to enter a Tartaros rift called “Dolos’s Stage of Trickery” here you will fight a group of enemies in 3 rounds. You will notice 6 targets that you can shoot with your bow. Just shoot the targets and let the beams or floor spikes kill the enemies for you. Be careful not to get hit by the beams or spikes.

Very important do not collect the treasure at the end of the level so you can come back into the rift if you fail to get the achievement. This is the only place I found so far that lets you use traps.

If you played on day one you will notice this is the same level that you could do for a few days to get coins to sell for shop items. It has been changed now but it may come back around.

After returning the essence of Ares to the God of War, speak to him again to receive two additional side quests. One of these quests is titled "Hot Pot" which tasks you with returning a pot to Ares. I happen to already have this in my inventory, but you may have to complete the fetch quest first.

Once you return the pot to Ares you will go inside it and enter the "Pot Ajar" rift. Here you will enter an arena and face of against three rounds of baddies. You will notice in each of the corners of the arena, there are sections with spiked floors set on automatic timers.

Simply lure the enemies over to one of the spiked areas and jump back and forth over the spikes from one side to the other. The soldiers will walk on them and start taking damage and eventually die (you don't need to trigger traps for it to count).

I like the first two rounds for this as they are mostly soldiers and you don't have to deal with any flying harpies or heavy hitting enemies. While there are more than enough chances during the first two rounds, the third round has additional soldiers as well.

Happy hunting.

Not as ideal as the above location, but incase you missed that and the 'Dolos's Stage of Trickery vault, here is another location. South of Athena's statue, you will find a vault called "Arena of Agility". This vault has timed lasers. They hurt like hell when you hit them. Luckily for you, the cause massive damage to enemies as well. I ran a figure eight around the two columns in the south of the arena to guide the enemies into them. I was able to complete all three rounds + the bonus round to unlock the chest with the lasers alone. If you unlocked Herkales's Pull, you can pull the harpies into them.

Directly south of the Goddess of Wisdom statue is the Arena of Agility. Inside the arena there are lasers between columns, the 4 in the corners and 8 along the sides. Even though you are facing "purple" level foes (gold nameplate) the lasers will kill them in just a few hits. I was able to get it right after I pulled the lever for the chest. If you hug the columns the beasties will kill themselves trying to get to you. You may need to dodge the minotaur's jump slam, but it shouldn't be hard.

For anyone missing this achievement in the actual vaults, I just got it while working through Ares fortress. I was standing between some laser beams and an advancing mod and they committed suicide (by running into the lasers ... I'd set my stone-clone on a pad that activated them) and the achievement popped. May be worth trying in Ajax's Fort if you missed it in an actual vault.

The quest I was on was called "Nest Egg".

Very simple to do, you can do this early on in the game, the vault that you can farm the achievements is called “Arena of Fortitude”. I was able to farm the achievement, when doing it kill the enemies keep going till you unlock if not you can restart the vault to keep farming it.