Puzzle Chronicles

Every time you level up, put your three skill points in Honour.
Honour will give you more experience per battle, so you level up faster (and get the achievement sooner). Plus you'll be stronger in battles.
Once you hit 25 or more, press A to accept and you get the achievement.

ALL your skill points should go straight into Honour with no exception. When you get to 75 honour, stop. There is a level cap of 50 so bonus xp will do you no good when you no longer level. If you're going for all awards (last achievement) then you need honour at 75 anyway (along with the other skills).

In Act 2 before the battle with the Master Slaver there is a village icon that you can use to pay to train your stats at 10x the level wanted.

You can use this to choose a stat and to improve it up to 25 for the achievement as you get gold.

It's much more cost effective though to level all your lower stats up with training cities and then to use the points from level up on your highest stat.

There are awards for getting your stats up to 75 eventually though so for all the achievements you'll need to get them all higher in the end.