Here's some darker themed ones, note healing reduction & modification can be done with
Bribe's Heal Event
Blood Price
- Target unit is cursed for a decent period, it deals 10% reduced damage, said damage instead heals the caster each time the unit would deal damage.
Blood Letting
- Curse target unit, Healing the target receives is diminished by 40%
Cleric's bane
- Curse target unit, if a unit would be targeted by a heal the caster of the heal will receive 65% of the heal as damage
Necrotic Cyst
- rapidly gestate a small tumor inside the target, target receives 25% less healing for the next 20 seconds, if healing on the target would reach over 40% of the target's maximum hp a small creature emerges dealing upwards of 40% of the target's maximum health based on how much the original target was healed. The cyst then crawls towards the original caster restoring 50% of the damage dealt, cyst has health based on the damage dealt
Pact of Blood
- Cursed target unit, caster receives 35% of healing the target receives if within modest range.
Cardinal Hour
- Curse a target unit, all healing towards the target is halted, after 3 seconds of not receiving a heal the target receives 150% of all pooled healing, casting a heal before the delay has lapsed resets the timer.
Misdiagnosis
- Curse a target unit, if the unit would be healed by any means it will receive a random leveled debuff sourced by the original caster of this spell.
Malpractice
- Curse Target unit, healing that would affect the target is instead treated as damage sourced from the caster of this spell, upwards of 20% of the target's maximum hp can be dealt before this effect is dispelled
Llyod's Talisman (Yes Dark Souls)
- hurl a holy talisman, all units within an small aoe receive cannot be healed
Effigy of Jealously
- Conjure a blue hewn crystal from the ground, all regeneration and healing is halted and instead stored in the crystal, after stealing 150 / 250 / 350 or 3 seconds or duration the crystal resonates with energy harming all those still within range from the stored amount.
Laudanum
- Target takes heals for 50% of its maximum over 15 seconds, however majority of it's stats are reduced by 35% until dispelled
Blood Transfusion
- Target a unit, unit & caster equalize health (+10/15/20% of caster's maximum hp) over 7 seconds.
EX: Lvl3 cast of Transfusion on a Footman that has 50/420 hp and caster has 350/700, they both will have 390 health at the end of the duration.