So framing the question.
Telossi & Sir Leon are side by side in a line fight. Their spell-afflicted charmed-or-undead friend Shin comes up and hits each with a wither.
Telossi has a purify and a purify strike.
While offensively Withered, the target may not make any offensive weapon calls or throw packets, but may block, use defensive calls, and touchcast spells. While defensively Withered, the target will take damage when blocking attacks with a weapon or shield as if they did not have the appropriate weapon skill(s) to wield them, may not touchcast or intentionally target themselves with a packet attack, and may not use Smart Defenses, but may still make offensive strikes and throw packets at other targets.
Purifying/Draining Strike [Curative Strike] - the character may, once per Logistics period per purchase, swing for “Weapon Strike Drain” or “Weapon Strike Purify”. Remember that since this is not a Carrier Attack (it doesn’t have a number attached) it is able to provide beneficial effects.
If he chooses offensively withered:
Can he use purify on himself? Yes - touchcast spell
Can he use purify strike on himself?
Can he use purify by touch on Sir Leon? Yes - touchcast spell
Can he use purify by packet on Sir Leon? No - no packet throwing
Can he use purify strike on Sir Leon?
Can he use purify by touch on Shin? Yes, but he doesn't have to accept it
Can he use purify by packet on Shin? No - no packet throwing
Can he use purify strike on Shin? No - offensive weapon call
If he chooses defensively withered:
Can he use purify on himself? No - touchcast spell
Can he use purify strike on himself?
Can he use purify by touch on Sir Leon? No - touchcast spell
Can he use purify by packet on Sir Leon?
Yes - can throw packets at other targets
Can he use purify strike on Sir Leon?
Can he use purify by touch on Shin? No - touchcast spell
Can he use purify by packet on Shin?
Yes - can throw packets at other targets
Can he use purify strike on Shin?
(
text in italics are edits based on the wording "but may still make offensive strikes and throw packets at other targets", which doesn't specify offensive packets. As Tieran pointed out below.)
I suppose the question is, does purify strike count as an offensive action? Part of me wants to say since it is being weapon delivered, it is inherently "offensive". So in the example above, while offensively withered it couldn't be used on any of himself, Sir Leon, or hostile-Shin; but that would imply while defensively withered it could be used on himself, Sir Leon, and on hostile-Shin.
Should Shin and Sir Leon have all the same answer above? I think the answer is yes, even though I can't know if Shin is either a living friend (packeted-purify|purify-strike would be helpful!) or a corrupted entity (packeted-purify|purify-strike is an attack!)
I'm also a bit unclear if while defensively withered if a packeted purify is acceptable against friends, enemies, or people you aren't sure of. I think without other ARC clarification, I'd say "offensive" means "ranged packet or weapon delivered" and defensive is "touchcast only". This would imply with a purify & purify strike Telossi would always be able to cure himself of Wither; and with a purify, he could always fix Sir Leon, but would have to either touchcast or ranged cast depending on which he chose -- and I'm not sure that's in the spirit of the Wither effect. But its really hard to otherwise define the edge case when we have the Shin-case.
(Sorry Shin for using you as an example. You've never been anything but the most righteous of earth casters to my knowledge and a loyal battlefield companion.)