I like the System of Memory. All they have to do right now is balancing of the skills.
3 Memory Slots are to much for a simple summon. Better decrease Memory cost and increase AP costs..or something like that.
I guess, nobody will use a Summon spell, when he could use 3 other Spells instead.
Also I like the idea to complete the memory system with Class-spezific slots.
Something like: All 3 points in Pyro you get one Pyro-memory slot.
And we should'nt forget that we get "skill-crafting" in the future. That will change a lot, too.
