mystic build

For mystic I personally think pure magic is the best build.

Every level put one point in Strength and the rest in magic. When you reach around 49 Strength stop put points in it and put all the rest of the points you will get in magic. In the level 90+ you will be more use with that , so when you will be level 90 check which gears you will plan for lvl 100 and if you see you need a few more points in Strength than add the ones you will got from a level up if needed.

The majority of high level gears/weapon requisite 54 Strength points, but some pieces like ornaments (necklace) and cape give a Strength points bonus so you don't necessary need to have a 54 Strength base. So at level 90-99 be sure to have a total of 54 Strength points to be able to wear the gears for level 99+.

In worse case if you have too much points in one or not enough in one you will be able to buy a reset note which is a item that make you able to reset some points.

I personally don't like vit build for mystic, but it's a personal choice, if you chose it, than that mean again the minimum Strength for wear your gears/weapon and the rest in magic and vit, example: every level put one point in Strength (like magic build stop at around 49), than one point in vit and the rest 3 points in magic.

At the end for these both builds you need to have at least total 54 Strength points for the gears and the rest in magic for pure magic build or some in vit if you chose to have a vit build. (these both build are for Arcane Armor)

There's some people that are Light Armor and Heavy Armor (if for some reason you just one of those than you will need more points in Strength and need points in dexterity), but it's really rare and i really not recommend that at all (specially if you don't plan to PvP and TW).