Disease Cloud

Required	Corruption Domain 4
Range	Centered on Caster
Area	5 yards x Rank radius, 1 yard x rank tall
Duration	Concentration + Natural
Casting	Verbal, Somatic
Cast Action	Standard
Cost	3 Mana
Effect	You generate a large billowing cloud of a chosen Disease equal or lower rank that moves away from your position filling an area of Rank cubic yards. Any target ending a turn inside the cloud must roll a Physical Resist or be infected by the chosen disease. Initially, the cloud limits visibility through/in it to 20 yards, however the cloud's density increases as the caster concentrates, reducing visibility by 2 additional yards each round, to a minimum visibility limit of 4 yards after 8 rounds. The cloud remains magically persistent as long as the caster continues to concentrate but acts like a natural fog. When the caster ceases to concentrate on the spell, the cloud will behave naturally, flowing with any present wind or breeze, burning off with any sun or dry air twice as fast as it's density can increase. While concentration is maintained, any natural wind may be resisted with successful casting rolls, however magical wind will require opposed casting rolls, or the currently held cloud will be broken free to dissipate. Losing a contested roll to maintain an existing fog bank will not break concentration, and the spell will remain in effect to continue to try to reform the fog bank as long as concentration is maintained.