20to50%increased damage from Impulsa, its not more damage, its increased damage.
the 5to10%monster life damage:
Quote
The explosion is a lightning secondary damage that hits and damages the nearby enemies. It is similar to Infernal Blow, Detonate Dead and Abyssal Cry in that the damage cannot be reflected and since it hits the target it is possible to leech from enemies.
Secondary damage: Detonate Dead's explosion deals secondary damage, hence it cannot be affected by stats affecting spell damage, including ones such as x% increased Critical Strike Chance for Spells. However the corpse explosion component of the spell will receive bonuses from elemental, area, and fire related stats.
you not need lvl26 unearth corpses in weapon poets.
you should get cwdt-unearth to fuel volatile death
can be triggered with scold bridle or heartbound