Board Thread:Naruto Discussions/@comment-36950799-20180918174601/@comment-26636534-20180928002039

Shadow clone/mass shadow clone seems to be the most practical. You could live out so many lives, studying would be a breeze, learning any practice based skill would be a walk in the park. The amount of experiences you could potentially make is astounding.

Kamui for safety, any harm that comes your way can be made harmless, plus teleportation for convenience and when you die, you can use Kamui to inhabit a friend's body. Pseudo immortality.