Harry Potter Cryptic

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Across
  1. 4. An old lady stripped for the warden. (6)
  2. 6. The lucky rat was having a ball! (6,6)
  3. 8. They dominate the growth of the institution. (8)
  4. 10. Sorcerer or not, he's brainy and tough. (6)
  5. 11. Hooter's having some trouble with his toupee. (6)
  6. 16. Bolt your doors, there's a flash storm coming. (9)
  7. 17. Drink in the atmosphere - be true, breathe, and spread your wings. (10)
  8. 20. Watching TV in Old Rome is just criminal. (9)
  9. 21. There's never a tender moment with this monster. (8)
  10. 22. He's got charm, period. (5)
Down
  1. 1. Chuck a pound in the hole to win the game. (9)
  2. 2. Crashing Ron's dad's car left a permanent mark. (4)
  3. 3. I can declare it's safe to eat. (5)
  4. 5. Boy, this almost isn't right! (3)
  5. 7. The song Draco sang to soothe the beast. (6)
  6. 9. Grading the top students lower by enforcing a cap. (7,3)
  7. 12. Stick to what you know and you'll go far. (4)
  8. 13. Almost a decision to make for the old crone. (5)
  9. 14. She is a hero of mine, one not to miss. (8)
  10. 15. Just a person having a large cup of tea, sort of. (6)
  11. 18. Handle a hard truth? It's a risk to comb through too finely. (10)
  12. 19. You can't steal Ernie's prefect badge, it's pinned to his uniform. (4)