劍走蜻蛉

the sword moves like a dragon-fly (modern idiom) / fig. unexpected winning move / unconventional gambit

double-edged sword / CL:口[kou3],把[ba3] / classifier for blows of a sword

to walk / to go / to run / to move (of vehicle) / to visit / to leave / to go away / to die (euph.) / from / through / away (in compound verbs, such as 撤走[che4 zou3]) / to change (shape, form, meaning)

see 蜻蜓[qing1 ting2]

damselfly / lacewing

sandfly