Just wanted to clear up some differences between the TCG and OCG regarding the use of priority.
In the OCG, you only retain priority to activate the ignition effects of monsters you control or Spell Speed 2 or higher effects. (You don't control the cards in your hand, Graveyard, RFP Zone, etc.)
For example, say you discard Destiny Hero - Malicious to Special Summon Dark Grepher. The summon is not negated by either player. In the OCG, you can only call priority on Grepher's effect whereas in the TCG you can choose to use it on the effect of the Malicious in your Graveyard instead. (Note that you would not be able to chain both effects together as they are Ignition Effects.)
Remember players, the game ends with you.