THe thing is at the end of changes, he was exceptionally dangerous. HE had no home, no office, no possesions, and forced to give up his daughter. He belonged to the winter queen so forced to stay away from his life, so all he was left with was his power and his enemies he has nothing to loose in attacking.
Powered by:WInter knight mantle, soulfire, and a map of the ways. HE could travel the world quickly and easily, he had the power and might of winter, and the control of soulfire, nothing binding him but the winter Q direct orders, and the winter queen would love for dresden to go on a killing spree.
MAvra know he has the knowledge of necromancy against the BCV, but he now has the power and control to take her and her kind down hard.
NIcodemimus while sees harry as a potential assest has fear of him, he knows how to harm him, has defeated a shadow of a denarian while keeping his magic, and he wields soulfire.
COwl or circle may have had enough of harry interfering.
MArcone is not likly as so long as the circle and other bad guys was out there, dresden would not remove the man keeping them at bay.
KIncaid specificly told harry that this was the way to kill wizards, and his family have been long time enemies of ebenezor.