SMITE

A good way to do this is in Conquest by playing support (or jungle/solo lane with HOG3). If you have Hand of the God level 3 then you can execute objectives once they hit 25% health. This is an easy way to make sure you get the kill and can even be used to steal when the enemy team is doing the objective.

The health bar will turn yellow the instant you can execute so you don't have to guess when it hits the threshold.

EDIT:
As of the latest patch Hog 3 does not execute at 25% health but instead does 1000 true damage to the objectives. This can still be used to guarantee the kill but high damage skills/ults are a better way to do this now.

Hey, I decided to write this solution to make life easier for others, because I was/am having trouble with this one.

First we need to know what constitutes a map objective in each game mode:

Assault: Only the main objective.
Joust: The main objective and the Bull Demon Enemy on the middle of the map.
Conquest: Main Objective, and the enemies on each side on the middle, Gold Fury and Fire Giant;
Siege: Siege Monster in the middle and Main Objective.

For the kill to count you have to land the killing blow.

Ok, with that in mind here's my solution on how to tackle the acheivement in an efficient manner:

Game mode: Siege
God: Artemis
Itens to buy:
Hide of the nemean Lion (Physical defense)
Bloodforge (Core)
Soul eater (Core)
Deathbringer
Ichivail

Strategy: We'll be aiming to kill the siege monster as many times as possible in each game, in Siege you can build up money faster than in Conquest so maybe with 12 min of game you'll have all the itens listed, if you're having a good game.
With that equipament the Siege Monster will be no match for you solo. Try to tackle it alone to land the killing blow. It respawns every five minutes so be there a little before to make sure the area is safe and to get dibs.
Getting the damage camp nearby helps when you're still at a lower level.

Of course the god and the itens are a mere suggestion, the important thing is to have life absorb and damage itens.

In a good the session youll be able to knock three to four kills, if youre boosting its much easier since you just have to wait for the monster to respawn.

Note: At the time of writting I haven't unlocked the achievement but I worked it up to 20% in only two matches.

In the end I hacked up my last kills on conquest with Bakasura with a similar buil from what I described above, In a balanced match you can get up to 5 Gold Fury respawns.

Sorry for any english mistakes.

I wrote the solution from memory so there might be a few minor mistakes, I'll fix them as I work my way toward the achievement.

This one will come pretty easily if you play as gods that have lifesteal in their core build. It is very easy to solo the gold fury dragon in this game if you have an item or two, so when no one is around it just go kill it by yourself. In a long game, you could get like 3 or 4 kills if that is what you focus on.

Hey Fellow TA Friends

Not sure which patch this came in but I can confirm that the Bull Demon King in Ranked 1v1 now counts as an objective kill (It never used too when I 1st tried this)

You must be lvl 30 to enter Ranked matches & also mastered the God which you want to use

Grab a friend & both set your servers to Australia region & both search at the same time on Ranked 1 vs 1. Fingers crossed that you both match up, this method works pretty much most the time but in case you don't meet up play the match out so you don't get a ban & try again. Both pick a god with a good Ultimate that does lot's of damage & rank yourselves up to lvl 20 by killing minions

Then take it in turns to kill the Bull Demon King. Whoever's turn it is 1st stand just outside the ring & let your friend batter him right down. When the Bull Demon King is really low health have your friend step out the ring as you enter & finish him off. Make sure you enter the ring before the Bull Demon King returns to his starting spot & regains health

Rinse & repeat! It takes a few mins for him to respawn so just chill but make sure you don't time out & leave the game!

The damage buff opposite the Bull Demon King can assist you if you are finding this a little difficult but this method should work fine for you

I am currently working on this & will have it in the next few days, this does take time & the game will stop at 120 mins

Any feedback on my method would be appreciated & I hope this helps you out

Peace