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'The first path is the easiest for you. Some of the best beast tamers in history have been those with your Ice Jade Crystal body for obvious reasons. Little brother just smells too good.' Ailsa giggled.
'This will be easier on your Mental Realm as well. Beasts are obviously more autonomous than undead creatures, so the pressure on your Mental Realm is only limited to the initial contract signed. In addition, beasts can improve very quickly. Their comprehension is mostly based on their innate talent, so they really only need resources to cross realms.
'Still, there are cons as well. Firstly, beasts aren't as unintelligent as humans paint them out to be. As of the Fifth Order and above, their thoughts are no less complex than yours. As such, they have their own societies and hierarchies as well. If a human suddenly starts accumulating vast amounts of their kind, it won't go unnoticed.