Every main event player gets Ursula, Deceiver, and 3 match wins earn Be Prepared. Qualifying for day 2 earns a playmat.
Further up: top 64 get Gaston, Superior Archer, top 32 get Madam Mim, Resourceful Trickster, and top 16 get another playmat. Top 8 win the gold, serialized Hades, Dark Usurper, limited to 250 copies. There are two more versions: 36 copies at the Championship and 8 at Worlds. Main Event 2 has no Hades; everything else is the same up to top 16.
Participation, 3 match wins and day 2
Top 64, top 32 and top 16
The three versions of Hades, Dark UsurperSource: Fanfinity (London DLC)