Forum:Scrap dragon policy

i have a face up scrap dragon and a set catd that is seven tools.my oponent has only a face down card the wabaku.i activate dragon eff and target ur set cards .im willing chain my 7 tools if he activates wabaku thats the point so how we do this part? i have to sent mine at gy first ?? then what if he activates hes card ? logicaly the oponent must reveal hes set card first since he has the prio to chain something in my eff