The spell Blightburn Weapon is a bit vague to me. Specifically when it says, "the weapon emanates an aura of radiation that causes blightburn sickness. This is as the disease, but with a 10-foot radius and a save DC equal to this spell’s save DC." The disease normally is a contact disease with a frequency of 1/day. Its' effect is, "1d6 Con damage and 1d6 Cha damage; contact is automatic when a creature comes within a 60-foot radius, and can be blocked only by lead sheeting, 1 foot of stone, or a force effect; Cure 2 consecutive saves".
When you're in the aura of the spell, I'm guessing you make a save every round, even if you're the caster. If you fail that save, do you keep making saves, or since you got the disease, do you follow the normal frequency of the disease, which is 1/day?
Check while in aura (10 feet not 60) and check to see if you catch disease. Then follow rules as normal. Check for everyone.
Seems really only useful for those with fire resist and disease immunity. Ratgolk alchemists may enjoy.
Actually a nasty effective buff with some planning, eg. If you've been throwing around Mage Armor before hand, or just have expendable (or immune, burning skeleton anyone?) minions. Con damage can be a huge takedown.
Surprisingly functional offensive spell - cast it on an opponent's weapon - he drops it or takes 2d6/ rd and blightburn in the middle of his/her position...