Thornmail needs to reduce attackers healing by 33%

Lets face it. turns tanks into walking HP Bars you can attack to heal yourself.

I say 33% because its not 50% like grievous wounds but its still will DO more damage if a fed is kiting the tank that has . This will make people not auto tanks for HP and make thornmail a useful item. Because by the time you get it, mages are strong, abilities are strong, and the one guy that auto attacks you to death has life steal or pen and barely takes any damage or no damage at all from your thornmail

When they stop attacking someone with thornmail, their healing will be back to normal and wont be op like a grievous wounds debuff.