New technique looks like it could be:

-A single target version of Geirskogul that's higher potency (useful for bosses and ST).
-A more potent version of Geirskogul (either ST or MT) that uses all remaining BoTD duration (best used before a boss becomes invincible or before a target dies).

It looks like a BoTD animation but the blue dragon flies up into the air and drops on the mob causing a moderate blue explosion.