Offline or online?

Offline, its pretty easy to achieve any of the goals playing against the AI.   For any of the skill goals you just need the killing blow with that skill to get credit.

Try opening with hammerslam, fight with basic attacks for a short while.  Once they are down to low enough that one hammer slam will kill them boulder roll to stun them and hammer slam to finish.

Rook is probably difficult to determine what got the kill with the towers on his shoulder always shooting.  Remember the goal requires 10 hammer slam kills in one game, so it won't be completed if you get any less than 10.

If I was going to try and complete this goal.  I would do it offline and setup a skirmish game.  Play on Prison as it is a small map.

Probably try 3-5 AI against just you as rook.  This way your teamates can't steal a kill and you will have plenty of demigods to kill.  You can make the enemy as strong or as weak as you can handle.

If needed pick your oponnent demigod.  I usually find Queen of Thorns fairly easy to kill, but demon assassin might be another good chioce since he has low HP.   Or other rooks so they are too slow to escape.

I had not developpe the towers of rooks for kill my enemy just with hammer.

Others achivements don't unlock when I make conditions. Exemple : kill a demigod with 10 lvl above you or below you.
Other probleme, I make conditions of achievement, and on my profil (http://pantheon.demigodthegame.com/achievements/player/91595/) it's not read achieved with image gold but 100% with image silver (normal)

Exemple :

Drain 100,000 points of health with Structural Transfer.

It's not very important but for me, unlock achievements show my progression in game (single or multiplayer) and see that I have 100% but no achieved is frustrating.

Solution ?