I would do the following:

• Make all reward cards tradable again
• Limit the supply of each reward card:
  -- Commons 500k
  -- Rares 180k
  -- Epics 30k
  -- Legendaries 12k
• Plan the reward cards to be available for 500 days.
• create a lottery each day for each rarity type.
• prizes are 1/500 of the supply of each card of the corresponding type.
• One Glint = 1 entry, 1 DEC = 1 entry, SPS gets converted to DEC, Credits get converted to DEC
• Burn 75% of the used DEC, the other 25% are revenue for the team.