▁for ▁one ▁season ▁or ▁the ▁other . ▁ ▁She ▁also ▁has ▁the ▁ability ▁to ▁see ▁and ▁speak ▁with ▁the ▁g host ▁of ▁Det . ▁D anny ▁W oo , ▁her ▁dead ▁partner , ▁and ▁others ▁dead ▁before ▁their ▁time , ▁murder ed ▁vict ims , ▁etc . ▁ ▁According ▁to ▁former ▁wiel der , ▁Joan ▁of ▁Arc , ▁during ▁the ▁Per icul um , ▁when ▁S ara ▁asks ▁her ▁what ▁the ▁W itch bla de ▁is , ▁she ▁answers ▁that ▁it ▁is ▁a ▁branch ▁from ▁the ▁Tree ▁of ▁good ▁and ▁evil ; ▁in ▁another ▁episode , ▁it ▁is ▁described ▁as ▁the ▁product ▁of ▁divine ▁al ch emy . ▁ ▁Flash back s ▁also ▁show ▁it ▁first ▁falling ▁to ▁the ▁earth ▁as ▁a ▁meteor ▁before ▁ending - up ▁in ▁human ▁hands . ▁ ▁Over ▁the ▁course ▁of ▁human ▁history / time ▁imm em orial , ▁the ▁W itch bla de ▁has ▁crossed ▁hands , ▁crossed ▁countries , ▁contin ents ▁and ▁cult ures ; ▁but ▁has ▁only ▁ever ▁been ▁w ield ed ▁by ▁women . ▁ ▁There ▁is ▁a ▁specific ▁female ▁blood line ▁that ▁the ▁W itch bla de ▁fav ours ▁for ▁its ▁w ield ers ▁( which ▁S ara ▁Pe zz ini ▁is ▁a ▁part ▁of ), ▁who ▁are ▁both ▁descend ants ▁and ▁re inc arn ations ▁of ▁a ▁previous ▁wiel der , ▁as ▁the ▁W itch bla de ▁has ▁directly ▁influenced ▁the ▁course ▁of ▁this ▁blood line : ▁ ▁When ever ▁the ▁W itch bla de ▁passes ▁into ▁the ▁hands ▁of ▁a ▁worthy