This is Glaceon. But not just any Glaceon. Oh no, this Glaceon has been through more shit than you or I can imagine, and she's finally snapped because of it.
This, my friends, is Disgruntled Glaceon.
And she know no mercy.
The origin of this picture's story is connected to a sketching thread on /v/ of 4chan. It's one of those things that you had to have been there for, but I think just the mere mention of 4chan is enough to make most people understand why poor Glaceon is now a homicidal maniac who will stab you with an icicle while your back is turned.