So, I was thinking... There's been tons of ideas on tweaks to HP mechanics in the server and I was thinking if it was possible to use Blessing of The Fairy (http://maplestory.wikia.com/wiki/Blessing_of_the_Fairy) for our HP gains. Basically 50 HP for every 10 levels our second character has. A level 100 "mule" or second character would grant your "main" char with 500 HP and viceversa. I'm not sure if this is practical or easy to code but hey, just my 2c.
