In function, there are multiple aspects to the Kitsune Fang. By default, it grants Defense +3. It also doubles any visible stat boosts on ally units within 2 spaces. It also provides the standard beast transformation effect of Attack +2 if he starts the turn adjacent to beast or dragon allies; or alone, with the cavalry effect of countering follow-up attacks and inflicting an in-combat Attack & Defense debuff when he initiates.
Grants Def+3. Grants allies within 2 spaces bonus to Atk/Spd/Def/Res during combat = current bonus on each of unit's stats. Calculates each stat bonus independently. At start of turn, if unit is adjacent to only beast or dragon allies or if unit is not adjacent to any ally, unit transforms (otherwise, unit reverts). If unit transforms, grants Atk+2, and if unit initiates combat, inflicts Atk/Def-4 on foe during combat and foe cannot make a follow-up attack.