Yes! You could have six different bosses (Nagato's 6 paths) at level 15, and it picks one at random.
When you beat it, it dies. Yet once you get to level 15 again, Nagato has already found and made another path so it stays six!
I love that idea!
EDIT (So no double Post):
The attributes would be added onto the current stats of the final boss. Also, higher resolution (and bigger) copies of the pictures are available.
First Path:
The Deva Path (天道, Tendō)
Possible Attributes:
Increase to ALL stats except SPEED.
Reason for Attributes:
The Deva Path was regarded as Pain's most powerful and cherished of the six Paths. Its main abilities revolved around gravity manipulation, allowing it to repel or attract objects or people. However, it could not perform these techniques in rapid succession, leaving it vulnerable for a short period of time after each use. This period of time between usages varied from five seconds to several minutes, depending upon the force of the repulsion or attraction that the Deva Path had used.
References:
Naruto chapter 367
Naruto chapter 422
Naruto chapter 423
Second Path:
The Animal Path (畜生道, Chikushōdō)
Possible Attributes:
Increased jutsu usage
Reason for Attributes:
The Animal Path's main abilities revolved around summoning various animals and creatures to aid it in battle.
References:
Naruto chapter 372+
Third Path:
The Preta Path (餓鬼道, Gakidō)
Possible Attributes:
Chakra Absorbtion (much like Kabuto but stronger)
Possibly make it to where Jutsu will not work on this path?
Reason for Attributes:
This path's "Chakra Absorption" ability was primarily defensive, since it was capable of absorbing any ninjutsu-related technique, thereby nullifying its effect.
References:
Naruto chapter 376+
Fourth Path:
The Human Path (人間道, Ningendō)
Possible Attributes:
Increased Taijutsu (More attack, speed and defense)
Reason for Attributes:
During Pain's battle with Jiraiya, the Human Path's eyes were damaged and it was left unable to see. For this reason, it used only taijutsu during the battle. The Human Path was later shown to have the capability of mind reading simply by placing its hand over the target's head, and could extort any information or secret being hidden by the victim against his/her will.
References:
Naruto chapter 376+
Fifth Path:
The Asura Path (修羅道, Shuradō)
Possible Attributes:
Increased Taijutsu (Strength, Speed and defense)
Reason for Attributes:
This body was very different from all other paths, being more like an android, as it had a number of body alterations. It was shown to have robotic inner workings, possessing six arms and three faces, and had a folded, serrated blade-like sash around its waist.
References:
Naruto chapter 379+
Sixth Path:
The Naraka Path (地獄道, Jigokudō)
Possible Attributes:
Increased Jutsu usage and strength
Reason for Attributes:
Although it was physically strong enough to lift a man with one hand, the only ability exhibited by the Naraka Path lay in the use of summoning the Outer Path.
References:
Naruto Chapter 379+