Percent Damage Reduction Spell

[akrep_ve_su]

I want a spell that when it is enabled, it should grant %50 damage reduction for incoming attacks. I tried entering negative value to "damage take" data of berserk ability but it didin't work; when this is done, hero takes no damage as long as the spell lasts.
I couldn't find a similar spell in object editor to give it a try. Any suggestions?

 

[Pharaoh_]

Use Defend; if you want a spell with duration through, you must base your spell off Howl of Terror with Targets allowed to Self, change the buff and add the Elune's Grace ability. Then, add your unit to a unit group and periodically (Every 1.00 second) check if the unit has the buff of your Howl of Terror-based ability. If it doesn't, then remove Elune's Grace from the unit.