A balance is created through the natural flaws of living creatures, and by not having a single entity represent both Elements simultaneously.
 
Every living thing draws the line somewhere - even those who offer unparalleled examples of virtues. Loyalty can only go so far before it becomes harmful, as it is with Kindness. For example, sometimes one must waiver undying Loyalty in favour of exhibiting Kindness to one’s foes or persuading an ally from making a mistake; and sometimes one must waiver unrelenting Kindness in favour of showing Loyalty to a cause, an individual, or even an entire group.
 
A world saturated in pure virtues would descend into its demise in much the same manner as a world devoid of them would.

Loyalty and Kindness exist in opposition to one another: To be loyal to one is to deny kindness to another. To be kind to all is to forfeit loyalty to any. For true harmony to exist, a balance must be struck.