Forum:Synchro Material and Formula Synchron

In opponent Main Phase, I have "Formula Synchro" and "Synchro Material" on my side, after I active and resolve "SM", can I immediately active "FS"'s effect before my opponent use his monster for Synchro Summon?--Lê (talk • contribs) 04:13, February 2, 2011 (UTC)