This attack is started by summoning a flock of blood-red "birds" that fly at the foe. When they make contact with the enemy, they explode into an iceberg that traps the enemy, damaging and "burning" him/her for as long as they are trapped inside. Each explosion also releases a burst of "ember snow".
This attack actually becomes stronger the more damage Savant had taken before using it.
It is the signature attack of Savant, so only he can use it.
This attack and its description is actually based upon a verse in the song "Falling Snow" by Agalloch. The verse is as follows;
Red birds escape from my wounds
And return as falling snow
The "red birds" themselves are the main focus of the attack.
"...escape from my wounds" - this references the fact that the attack rises in power the more damage Savant has sustained beforehand.
"And return as falling snow" - this references the fact that after the red birds explode into ice, they release "ember snow", which would be the "falling snow" mentioned in the verse.