All attacks against a marked target including spells increase target's DamageScale property by +0.2 for 20s duration. In the majority of cases, DamageScale equals 1.0, so Mark of Death usually translates into an effective +20% damage bonus.
Conjuration time: 1s.
60 Threat is supposed to be drawn from the target. As of Patch 1.02, no Threat is drawn.