Poison Spell at Town Hall 8: max level 2. At Town Hall 18 the cap is level 12. It unlocks at Town Hall 8. Max level per Town Hall: TH8 2, TH9 3, TH10 4, TH11 5, TH12 6, TH13 7, TH14 8, TH15 9, TH16 10, TH17 11, TH18 12.
Tap a Town Hall to open this item there. Dashed: not available at that Town Hall yet.