i am confused about the rewards

so at the end of the race season i unlock lets say volls devotion on what characters exactly?

Crude basics on prizes, from the FAQ post...

• Once enough points for a particular prize threshold is reached the prize will be automatically added to the account
• Prizes will be awarded in a Remove-Only tab with the event title as the name
• Prizes can only be removed in one league
• Reward Tabs are only available once a league is four weeks old

More detail... For the sake of consistency in the example... In the next event, A2TMP Piety Kill (MDC061), your account hits the 1000 race points threshold. Congratulations! Once the character is migrated to its parent league (in this case void), and your points from the event are added to your total, the system will generate the prize for your account.

The prize will be in a tab labeled, "A2TMP Piety Kill (MDC061)(Remove-Only)." Because the Prophecy Challenge league is more than four weeks old you will be able to see this prize tab on any character you have in Standard, Hardcore, Prophecy, or Prophecy Hardcore. But you only have ONE of these prizes, you are just able to take it out in any of the four current leagues.

If you do not want to use the item in any of the four current leagues, you can keep the item in its prize tab for future league usage.