chaos sorcerer

my opponent has a face up monster and a face down bott .
i sommoned chaos sorcerer and he activateed bott . can i still activate sorcerers eff to remove the face up monster?
(i think it works cuz its prio)

answer is no. In order to use priority you have to declare that you are using your priority when you summon the monster. You cannot wait for your opponent to activate BTH.

when you summon a monster you have the priority to use an ignition or spell speed 2+ effect before your opponent can respond. If you didn't use his effect at this point, and allowed your opponent to use BTH, then you can't go back afterwards and say I want to use my priority.