Energy Draining Leash - The Archons land a strike on Raziel which opens a spiritual tether through which the Archons can drain further energy. Only striking the enemy or retreating to a safe distance could break the bond.
Like other Spectral fauna, the Archons are only found where they are required as enemies. Attempts to enter the Spectral Realm in Kain's chapters through Debug menus or the like will include few Spectral effects and no Spectral enemies.
The Draining Leash ability of the Archons is actually listed slightly differently for the two Archon variants in the official guide. The Reaper archons variant is listed as "Draining Leash", while the Dreadnaught variant is listed as "Energy Draining Leash" - the similarity of the attack is noted however and the only difference referenced is the tendency of the Dreadnaught archons to use it as a follow up to their Projectile Hold attack. Visually and in gameplay terms the two leash attacks seem to be virtually identical.
Although it is only explicitly listed as an ability in Defiance, the Draining Leash ability bears a remarkable resemblance to the unnamed ability used by Spectral entities such as Vampire wraiths, Revived vampires and the revived Dumah to drain Raziel's health in Legacy of Kain: Soul Reaver - both are used by species and individuals that have adapted to the Spectral Realm and learnt to consume souls or soul energy, both require an initial wound to be opened, both consist of a similar blue/purple band and both form a 'leash' of sort that can be broken by distance or damage. Arguably Draining Leash may be considered to be the same ability with updated visuals. Another ability that is highly related is Constricting, which again uses a similar spectral band and may have been directly developed from the vampire wraith ability.[Defiance][Soul Reaver]