I actually have to wonder who is the better ninja to "build" now that weapons and skills can be inherited. Most of them are bad/poor in comparison to Kagero barring one Gaius.
Kagero (no weapon): 31/35/32/22/28
Gaius (no weapon): 39/32/36/22/19
Gauis has rather crap for defense compared to Kagero, and he has a lower attack (Kagero's is simply monstrous) stat but his speed is a good bit higher. But with the way that Poison Dagger+ makes Kagero into an overkill glass cannon, it may round off Gaius in a more balanced manner and allow him to double more units than Kagero could have hoped to accomplish. He'd be extremely glassy, though. He cannot be doubled by Linde, however.
Gaius w/ Poison Dagger+
Life and Death 3
*stuff I can't think of at the moment*