Fan Ideas - Characters

I don’t know how to do this but I will explain my character (try to atleast) 
Zenith starts with 4 burning hearts, which are special in which each heart lost gives a double multiplier to damage, and makes you take double the damage, this effect has a maximum of 4 stacks and all damage is 1 heart or more at base.
Zenith starts with the item Unyielding Flame
on use, sets you to 1 heart and blocks the next instance of fatal damage, however this comes with a consequence. when you block an instance of fatal damage you will lose your best item.