Pretty scary. So all the pirate lords throughout the world team up against him. They agree to hold a meeting at Shipwreck Cove, where all the Brethren Court councils have alwasy been held. Of course, if Beckett wants to eliminate piracy throughout the world, it would be a lot easier to do so if he could just get all the piarates together and kill them at the same time. Of course, he'd need quite a fleet but it would still be a lot easier to do than hunting down every single pirate and killing them seprately. So the meeting at the Brethren Court provides the perfect opportunity. But like most pirate locations in the pirate world, it's hidden and hard to find unless you know where it is. So it's actually Will Turner who leads Beckett to the secret meeting in hopes that it will somehow gain freedom for his father.
Meanwihle, back at the actually meeting, one of the pirate lords can think of a solution as to what to do about the grwoing threat. They only become more frantically confused when they were that the EITC armada is actually outside the city waiting to destroy them Jack and Elizabeth try to get them all to fight. Eventually, Jack elects Elizabeth "king" of the Brethren court, so she declares war on the armada. They brace themselves for war and sail out to face thier enemes. However, the armada is a bit bigger than any of them expected, so they try to negotiate something instead. They call a parlay between Bekcett, Jones, Will, Jack, Barbossa, and Elizabeth. this parlay doens't accomplish much though accept that Jack returns with Beckett and Jones while Will goes back to the pirates with Elizabeth and Barbossa. I'm not so sure why they dida ll that for a little trade, because in the end, King Elizaeth just resolves to fighting the huge armada anyways.
Barbossa tries one little trtick before plunging into war though. He releases the sea goddess, Calypso, who was trapped in her earthly form as Tia Dalma. Since it was originally Jones who told the Brethren how to trap her in the first place, Barbbossa hoped that she would help them out in defeating him. But it doesn't look so favorabel for them, so a lot of the pirates begin to loose hope. They want to be cowards and just surrender before any of them die. However, Elizabeth won't let this happen. She conducts this pretty impressive and pursuasive speech to give them the encouragement to fight. That's when "What Shall We Die For" plays.
It's so epic because all the pirates of all around the world get worked up and agree to take down this armada. It's pretty scary: to have hundreds of pirates chanting and going after you. So despite the odds being incredicly against them, the Black Pearl, captained by Barbossa at the moment, leads the Brethren court into battle.