Réponse trouvée dans l'Errata & FAQ d'Aristeia : Maximus peut prendre l'ensemble des dommages, même s'il y en a plus que son nombre de points de vie.
Q: A Gata, in contact with her ally Maximus, suffers an Attack from Miyamoto, that ends up in a result of 7. How is the Automatic Skill “Behind me!” applied?
A: Before inflicting the Damage you must decide how much of that Damage is suffered by Maximus, and the rest is applied to the Target of the Attack (in this case Gata). In our example, Maximus could receive 6, so that Gata will only suffer 1.
Q: How much Damage can Maximus take with his Automatic Skill “Behind me”?
A: He can take any amount of Damage, even if this surpasses his Wound characteristic.