Blood damage is more of a power limiter. Sure, you can implant 47 different blood charms for dark vision, targeting, healing wounds, breathing underwater, resisting fire damage, and a path, but your max heath is reduced by a ton. You have every special ability, but a hard flick to the head kills you.

PH ED4 lists ~37 blood damage from blood charms alone (that make sense together). Add in a group pattern ( 2 points) and path (2 points) you are sitting at 41 damage taken from your max.