Since Deathly Aura is a Reaction, it's not subject to the rule of presence or the rule of location.
Does that mean I can target Deathly Aura on a Samurai at home, and perform an action on that Samurai, as long as the battle action performed by the Samurai satisfies or circumvents the rules of presence and location (Yojimbo's Glory, for example)?
Deathly Aura: Reaction: After engaging, if you are the Attacker, choose your performing Samurai: You have the first chance to take a Battle action in this battle, which must be performed by that Samurai.
Yojimbo's Glory: Battle: Target your unbowed Yojimbo Personality: Move him to a location where you control a Shugenja. You may take an additional Battle action, which must be performed by the Yojimbo.