cause it's time to grind.
evolving system is a new addition to KMS, and it is broken to bits and pieces.
you can get cores that add/change the monsters in the system.
you can get a core that spawns shadow empress or shadow cygni.
you can spawn manon, griffey and pianus.
you can also increase the levels and amount of HP on the monsters.
if you go to link 9 with a 20xHP, 20% party exp and 30% HP core, you can get this:
1071702 exp per kill.
549591 from the monster
164877 from item pendant
247316 party bonus(it's a PPZ)
54959 from exp elixir
54959 from merc link