Chivalry isn't a problem - Once the standard (non-super) slayers started doing 3x instead of 2x, many Sampires dropped what little they had (after all, they can use a recall charge from a spellbook to move around if combat close, and can just cast wraith form to travel at 100% with recall when not in combat, and just recast vamp form later - and of course, Whammies don't even have to leave wraith form).
One of the issues with Whirlwind attack (of the non-bushido variety) has always been that, unless a weapon is Spell Channeling, it takes damage from EVERY target hit by the whirlwind, if one or more of them have auto-damage (example, slimes at Barracoon first stage). If there's not any of those, then every target hit gets its own "damage the weapon?" check (and both types of damage may occur, theoretically).
On the Sampire tangent, I think that really, the 4 skills of Bushido, Ninjitsu, Chivalry and Necromancy are significantly incompatible with each other.
1 & 2 are supposed to be opposites, as are 3 & 4.
Ninjas are Stealth (most forms are meant to blend in with nature or domesticated creatures), while Necromancy is hardly subtle (and its alternate forms are all undead or demonic - something one hardly use to walk next door to borrow a cup of mandrake from the neighbors, inside a guardzone)
Samurai are into Personal fame and honor, Paladins live for showing honor to the masses.
One way to reflect that, while still allowing the occasional fallen knight, corrupted Samurai, etc. would be to make it where having 60 or more real skill in one of the skills, causes all the others to function at half their modified skill level, based on whichever is higher. So, a Samurai with 80 real Bushido, could only cast necro or chiv spells at a maximum proficiency of being 60 skill in those, and only if somehow he had a modified total of 120 in them, with the real skill points under 80. If two or more skills tied, the order they fall in the skill list has precedence.
This would make Sampires have to choose to be primarily Necromancer, or choose to be Whammies that are Samurai with a weak necro ability, for example. Corrupted knights (or necros turning to the light) with both Chivalry & necro would actually have their attributes and level of corruption based on which skill was the higher (And that would actually factor into the RP aspect of such a character). And so on...
. The day they do something about that is the day you see UO items go back up in value.
