Just a little idea, could possibly use favor orb and memory orb mechanics...
I believe we use to have overflow pools for certain skills, such as trading and stealing. This idea would bring them back. So if'were ever in a position, say, selling pouches as a trader and your mindlocked, you could whip out this item, drain your stored exp into it, and continue on, not worry about 'wasting' anything. Could be for specific skills or whatnot, doesnt matter. I'd like them to be sold in the LTB store, but if its MT only, thats ok too.

-Mind Cube (name doesnt matter, just dont want it to be confused with memory orbs)
align cube <skill>
focus cube (drains skill into cube, after a period of time, say, 6 hours, you can invoke cube)
invoke cube (all skill drained into the cube goes back to you)
upgrade with potency crystals to add a multiplier to it (x1.25,x1.5,x2,x2.5,x3)