
Ok, implanting a Blood Charms costs you -1 Toughness per charm.
As a loooong time SW & ED GM and player I can tell that that is a huge penalty in SW and I doubt any player would ever take any Blood Charms

Before the rules are sent off to the printers I have a couple of alternative suggestions that may make taking Blood Charms at least tempting.
Suggestion 1: Implanting a Blood Charm costs you nothing (except sp) but when you use the Blood Charm is causes 1 Fatigue, that can't be recovered for 24 hours. This way you really have to be desperate to use the charm, but it is there if you really need it. As a level of Fatigue gives you -1 on all rolls it is a pretty hefty penalty and as there are no Edges that allow you to ignore Fatigue this is a nice penalty, especially as the benefits of Blood Charms are not really that great.
Suggestion 2: Implanting a Blood Charm, like living armor, give you -1 on your vigor rolls. Not sure if this is the best way to go as to many minuses will get you into big trouble.
Cheers, Chris