Bring back the cube upgrade system!
End game maps need only min lvl80 ancient manastones (lvl6o are now redundant except for newb areas)
Let Lacrum mini bosses drop something useful. (eg ancient with a chance of legendary fragment)
Bring back the old stone morphing recipes to run alongside the new shugo coin ones.
Apply group bonus or rewards for carrying a newb in some instances.
Make it so all who participate and conquer an alter has a chance to get a ultimate stone coupon (not just the largest legions who generally don't recruit newbs)
It's late but the above is a good starter.