Reducing Healing

Hey,

I want to create some Custom Heroics. And in this Heroics the Damage and Healing from Players should get reduce about 30-40%.
(For Example Prayer of Healing do 10k healing instead of 13k Healing)

I tried to change a “Test” spell from Blizzard like “Hot Food - id 12” adding attributes like:

SPELL_ATTR0_HIDDEN_CLIENTSIDE and SPELL_ATTR1_DONT_DISPLAY_IN_AURA_BAR

and adding debuff aura:

spellInfo->Effect[0] = 6; // Healing Debuff
spellInfo->EffectApplyAuraName[0] = SPELL_AURA_MOD_HEALING_PCT;
spellInfo->EffectBasePoints[0] = -40;
spellInfo->EffectImplicitTargetA[0] = TARGET_UNIT_CASTER;
spellInfo->EffectImplicitTargetB[0] = TARGET_UNIT_CASTER;
spellInfo->Effect[1] = 6; // Damage Debuff
spellInfo->EffectApplyAuraName[1] = SPELL_AURA_MOD_DAMAGE_PERCENT_DONE;
spellInfo->EffectBasePoints[1] = -40;
spellInfo->EffectImplicitTargetA[1] = TARGET_UNIT_CASTER;
spellInfo->EffectImplicitTargetB[1] = TARGET_UNIT_CASTER;

But this didnt realy work ingame and i think there could be a better solution then adding them a Debuff that handle this(?).

push?
No one has an idea to do this?

push

push

I want to create some Custom Heroics. And in this Heroics the Damage and Healing from Players should get reduce about 30-40%.
Someone an idea of how to do this?