The Munin Howl is said to be a werewolf's greatest and most lethal technique. Once activated they are able to channel the collective might of their ancestors into their physical form. That includes their rage, malice, aggression, hatred memories, and experience, concentrating it to such a degree as to enhance their speed, strength, reflexes, endurance and spiritual energies to unprecedented levels.
Its power is so great that it is said to be only harnessed by the most talented generations. These ancestors are also the ones whom once wielded the werewolf's current weapon the Bloodline Blade.
The Munin Howl is normally seen when a werewolf is engulfed by an aura of golden spiritual energy, which then later expands and the spectral form of a wolf can be seen looming behind the Lycan that is charging his power. However, this color of gold is more commonly attributed to werewolves whom are not in possession of a Bloodline Blade but it means not that all lesser werewolves can access it as it is still an incredibly difficult power to master.
The wolf specter itself, can also be the spirit of the blade of which they carry, the Bloodline Blade; example being when an alpha wolf wields the blade Fenrir, the spirit of the mighty Wolf of Destruction can manifest behind them and the lycan can channel Fenrir's power through them as well. The specter of the wolf that engulfs the lycanthrope that is activating this power can also coat the wielder of the evoker of the Munin Howl, acting as though it is a secondary layer of body added with the werewolf's already formidable power. The spectral form of the wolf spirit can also fight alongside the wielder and the conjurer of the power once they are in perfect harmony and sync towards one another.
However, this is actually an extra step of the transformation, and is quite dangerous for the wielder of the blade. If they are not in sync with the spirit that resides in the sword, the spirit will lash out and the transformation will be cancelled, leaving the lycan severely weakened and drained.
Once in full action, the Lycan who is under the transformation is now capable of fighting through the experience and memories of the original elders of the Lycanthrope clans making them an even more formidable force to be reckoned with. When it comes to the additional step by channeling the power of the wolf spirit that resides in their blades, the color changes to that of the spirit itself, for example being the spirit Anubis' signature color is green which is associated with necromancy in common interpretations. And thus the golden aura will shift into that of a green aura.