don't forget you get 5 wisdom minimum from the staff you equip and also an easy 10 wis from the glasses and doctor set adds wisdom also you don't want above 99 since then you run into the issue of stat cap 

Here's more of a question... Why do you have so much WIS stat if at 50 WIS stat you can already kill almost anyone in 2-3 seconds using lightning magic? It would be even better to invest in something else like CON stat so you can release more lightning without fear that your stamina is over + you can travel long distances + you can heal more wounds when half a day passes + you can carry more things... or just to level up some SUR stat that will protect you from blowing yourself up with your own spells + you can make more food and other useful things.

Ideally, the perfect Mage Lona it’s something like:
0 COM, 5 SCU, 50 WIS, 10 SUR, 10 CON.

and then you decide for yourself what to spend more on and less...

For example - I found that SCU stat are in principle not worn by any regular class (Warrior, Mage, Nympho) so much than something else especially if you have a Moot race which gives you 5 extra points of SCU stat and that’s kinda enough for steath because 5 SCU + Dirt SCU buff = 7 SCU stat that already allows you to hide from enemy sight even if you’re just standing and you can also wear some dress like Hunter Set (Leather Set) that also will help you to hide from sight.