the undead heart

this spell allows you to become invincible to damages. when the player casts the spell the heart of the player will be out of their body covered in dark shadows.

this will allow the player to be able to take 2d10 dmg without lossing any health.if the dmg is more than the number the player rolled, the player have to divide the number form the dmg.at higher levels the spell will be able to define more dmg, as the number of dice increases.  

also the player has to protect their heart, shall the heart be dmged the player has to double the amount of dmg and take that. 

this spell ends for one round and the heart has to go back to its owner in 1min.if not the player would go unconscious and if the heart is not returned in 2min they fail 2 death saving throws.