http://www.youtube.com/watch?v=M_4REgOsv_A
The stage is 7 pages on hard.
A fun technique to use, Ice Barrier is the Alchemy skill of using weakened barriers to spread multiple times on enemies and to refreeze strong enemies over and over. Though it is a bit pratical, it's really more of a fun skill to watch. Of course you can use normal ice spears too.
Because the monsters here have 1k~1.4k hp and with their defense/prot, the Ice Spear Crystal I used only does 800~1000 damage, so thus using the barriers refroze them twice to effectively kill them as well as spread to nearby enemies.