Related Clues:

• I finish up being bitten by sea creature, very hard
• Diabolic? Finished, as it turns out
• Terrible demise near island, getting eaten by sharks?
• Cryptic finished, as you'd expect one to be?
• Indirectly seek to compass conclusion — I like some Sudokus
• Extremely difficult
• This Sudoku finished after a struggle?
• Wearing Christian symbol, I stop being demonic
• I stop to delve about for, wicked though it is
• Pal losing rag initially -- his indisposition is extremely unpleasant
• Like tough crossword I finish in school
• Very hard one to complete, outwardly brill?
• Finished puzzled? That's typical of the Toughie!
• Possible description of sudoku, kind of finished
• I stop tucking into cod, say — far too tough