As a fan of web novels, I don't have my own subjective views, nor do I have any preferences or prejudices towards anime. However, according to my knowledge of online literature, the following are some of the anime endings that have not yet been determined or there is a great deal of uncertainty, so it may not be possible to see the complete ending: [1. The Blade of the Destroyer: The anime is still being serialized. The author, Tanjiro, has not revealed the final ending yet.] Therefore, even if the anime is completed, we will not know the complete ending. 2. Sword and Sword Art Online: This anime is still in a series. The story is set in a virtual reality world. The ending of the anime has always been controversial. It is still unclear whether there will be a complete ending. 3." The Attacking Giant ": The anime has been fully serialized, but the story is not over yet. As the author Alan is still in a coma, we can't know the final outcome. 4. The Gate of the Stone of Destiny: The anime has been completed, but there are many uncertainties in its ending. Due to some scientific issues involved, the outcome may need to wait for more research and explanation before it can be determined. It should be noted that the uncertainty of the ending of the above anime does not mean that they do not have a final ending. It may just take more time and plot development to reveal the final ending.