You have to earn 250,000 Points by winning a duel against Pegasus at the Gate during the event. The amount of Points you gain is based on a Duel Assessment. For details, check the link to even details page above.
Are missions only counted when you get the character unlock missions or your actions before it already start those missions cleared?
For example,say I picked Kaiba as my starter.I obviously will have used Blue Eyes far before I got to Stage 15. One of Yami Yugi's Stage 16 missions is to use Blue-Eyes once,will I start the character unlock missions with this mission cleared for having used Blue-eyes before it was unlocked?