(Quick easy summary for the most common type of demon tool relationships.<br/><br/>The easiest three versions are probably:<br/>Master<br/>Partner<br/>Servant<br/><br/>The relationship Sin has just forged with hers, is one where she is the master. Basically in this sort of set up, the wielder has to prove themselves as worthy through some sort of trial or challenge. Once they do, the demon tools will serve that person. This sort of arrangement usually has the least drawbacks or catches to it as it's based on a quantifiable respect. She's proven that she's strong enough to wield the weapons, so the weapons will obey.<br/><br/><br/>A partnership is like what Valspan and his doll have formed. This is possibly one of the most interesting ones, because there's no clear guidelines or rules to it. Basically, the two have no official agreement, only shared interests and goals. On one hand this is good because Valspan doesn't have to give up or exchange anything, however he's not guaranteed anything either. Like Ryuk from deathnote. He and Light are great friends, but once things get boring or look bad, 'sorry bud, it's been fun but I'm out.' and he simply moves on to the next interesting thing because there's no real reason to stick around. This means that as long as Valspan and the doll share the same interests and goals, they'll be a great team, but if the doll ever finds anything more interesting it likely wouldn't even hesitate to move on to someone else or even change sides and turn against Valspan if that option seemed the most entertaining.<br/><br/><br/>The servant would be if Seydon was willing to give something up in exchange for power granted from the tool, or more accurately the ability to wield it. Usually this is the most dangerous option as it costs the user something in exchange. Blood, or parts of their life are the most common exchange. Like an enchanted sword, it may be the most powerful weapon in existence able to cut down any foe, but every time you swing it it takes a year off your life. It's powerful, but there's a heavy cost. In this relationship the demon is more in charge than the wielder. Sometimes the wielder is able to overcome the weapon in a battle of wills to cancel out the negative effects, but it's still a very dangerous and risky way to go about things.<br/><br/>Of course, even trying to become the weapons master is dangerous, as if you lose the challenges, you could lose something else as well, like a hand, an eye, etc. or if the stakes are high enough, the demon might just claim you entirely, like how Spectra makes deals with people, except not necessarily with any pleasant or nice intentions behind it.<br/><br/>There's your quick and easy overview of demon tools.<img alt=":)" src="./images/smilies/smile.gif" title="Smile"/>)