Like the Magic Treasure, Soulbounds are personalized by a Contract of some sort. In this case though it is not an Object but a Companion. Also referred to as Familiar or even Pet. Soulbounds can be any kind of Beast or even normal Animals.

Contracting a soulbound has similar rules as creating new Ki Arts. Depending on its affinity it is more or less compatible. Potential Soulbounds with the exact same Base and Sub Essence are way easier to contract with as well as more loyal later on. The Chance of successful contraction depends on the Character's Level and the Beasts or Animals Level. The Higher above the level of the beast above the character, the lower the chance. The same goes for differences in Essences.

• If different Base Essence = -75%
• If different Sub Essence (Stronger (C>SB)) = -25%
• If different Sub Essence (Neutral (C>SB)) = -50%
• If different Sub Essence (Weaker (C>SB)) = -75%
• If different CRank<SBRank = -5% per Rank if SB is higher, +5% if SB is lower ranked
• If different CLvl<SBLvl = -1% per Level if SB is higher, +1% if SB is lower in level

A Soulbounds and Masters life are bound to each other. If the Master dies, the Bound one dies as well even if it’s natural Lifespan surpasses those of its Masters. If a Soulbounds natural Lifespan is lower than its Masters, the life gets expanded as long as the contract is intact, but it also requires Cultivation of its Master. If such a contract is severed, the Soulbound dies on the spot. Severing a bond uses up half as much Cultivation that was used to create a bond.