Okay, so for those who haven't seen my other Avatar-related questions, here's the pertinent information:
Avatars are created from Ether, or solidified Mana, but have a real form (if it's an animal, it has organs. If it's a machine it has real mechanical parts). Avatars are created when someone puts a piece (a "spark") of their very soul inside an orb of Ether, which creates an Avatar linked to them. You can only have four Avatars.
Avatars have magical abilities (Ex: a Bullet Shrimp fires bullets of magically compacted air, a Fire Salamander can spit flames) and some can cast spells. An Avatar's age at creation is determined by how much their creator has developed at the time they were created; in other words, immature people create juvenile Avatars, while mature people create older Avatars.
Additionally, an Avatar's growth rate is irrespective of their species and is instead determined by the rate at which their creator grows and progresses. Over time, Avatars become better versions of themselves, so self-improvement is key!
Avatars and their creator share information telepathically whenever they're within six miles of each other. In other words, the creator knows what the Avatar knows, and vice versa.
Last of all, Avatars don't usually tire, except from demanding work (combat, construction, and the like), don't require food and water (but need air), and can only die from suffocation, injury, poison, or old age.
This is where Inheritance comes in. Let's say someone's Avatar has become famous along with them. In that case, the Avatar represents their legacy and lives on for as long as he (or the Avatar) is remembered. That's all that's currently known about Avatar lifetimes; no one knows what determines an Avatar's lifespan after their creator passes, but plenty of guesses have been made.
An Avatar whose Creator has died can link to someone else, becoming their Avatar. This is called the Inheritance Principle, and here's the problems with this:
If the Avatar's creator was someone's parent, their child can take the "lost" Avatar as their own even if they have four Avatars already. Ditto if they were survived by a loved one.
Once an Avatar is Inherited, they pass on the power inside them (the power of their creator) to their new owner. They then live and develop with the new owner. This allows an Avatar to become insanely advanced as they are passed down from generation to generation, and as they're passed down, they're also making the recipient more powerful and sharing their accumulated wisdom and experience.
So, my question is: Is this Inheritance Principle too powerful, and if so, what should I do to balance it?