In general, MP is better if you use your ability, and Wis is better if you are not using your ability, similar to HP vs. Vit.
For a Wis ring to increase as much magic as an MP ring does, you will have to go for some number of seconds for it to do so. This number varies depending on the rings. T1 Wis rings will add 40MP in 3:42, while T5 Wis rings will add 140MP in 4:51. If you can avoid using your ability that long, Wis is better. If you must use your ability faster than that for any reason, MP is better.
This chart compares MP and Wis rings of different tiers. The number is how much time, in minutes:seconds, must pass between ability uses for Wis to be better than MP.
 |
 |
 |
 |
 |
|
|---|---|---|---|---|---|
   |
3:42 |
7:24 |
9:15 |
11:06 |
12:57 |
 |
2:13 |
4:26 |
5:33 |
6:40 |
7:46 |
 |
1:51 |
3:42 |
4:37 |
5:33 |
6:28 |
 |
1:35 |
3:10 |
3:58 |
4:45 |
5:33 |
 |
1:23 |
2:46 |
3:28 |
4:10 |
4:51 |
