Each 25th Anniversary Tin: Dueling Heroes includes 3 x 18-card Mega-Packs, each with TWO Prismatic Secret Rares, two Ultra Rares, a Super Rare, a Rare, and twelve Commons.
Full tin breakdown:
6 Prismatic Secret Rares
6 Ultra Rares
3 Super Rares
3 Rares
36 Commons
(and 1 Quarter Century Secret Rare – see below!)