Well, you guys may find my ideas below crazy but could be a good starting point:
[option 1]
1 slot
5% Redux
23% Reflect
25% Movement Speed *
Decrease Max HP by 15%
+15 Vit
+15 Agi
*These movement speed will be very useful for last minute in WoE. So like this will be for switching only when you are about to go th But for it to be less OP, you lose some HP.
[option 2]
2 slots
23% reflect
5% Redux
25% Movement Speed
Decrease Max HP by 25%
+15 Agi
+15 Dex
+15 Str
Yes. 2 slots is CRAZY! But again, it's a starting point. :)
What I learned here in fRO is you give and take. So if we give these good stuff, we need to take back the max HP and stuff.