Witch at Town Hall 18: max level 8. It unlocks at Town Hall 9. Max level per Town Hall: TH9 2, TH10 3, TH11 4, TH12 5, TH13 5, TH14 5, TH15 6, TH16 7, TH17 7, TH18 8.
Tap a Town Hall to open this item there. Dashed: not available at that Town Hall yet.