I must admit I found the ending to Bram Stoker's original novel Dracula to be a little disappointing. True they found and destroyed the monster, but after such a long chase and after such a difficult time locating and besting the elusive creature I found myself wondering, Is that the best they could do?
The story was completely engaging. The characters were either much beloved or else quite loathsome. It was worthy of the best comic book copy, and was a fun read with fresh vocabulary to brunch. Chasing down the source of their troubles proved a task that took some doing, but at the end there were no cries from Dracula, no protests, no pleading, no lingering pains of death in exchange for the cruelty he had dealt in his unnatural undead life. It was, in my estimation, a limp end to all their struggles, although I liked the notes that explained how life continued in the resolution phase of the novel.
We must as writers guard against letting down our own audience. We must leave them cheering on their feet instead of raising their eyebrows and wondering if all the imaginary journey had been worth its conclusion. For some it may have been; but we want them all captured, unquestionably enthralled by our performance.
P.S. First read the novel if you haven't ever, then see how you would rewrite its ending. You're free to play with that one; it's in the public domain.