One interesting 'critical point d gray man fanfic' could be one that focuses on the backstories of the minor characters in the original series. For example, exploring how some of the lower - ranked exorcists came to join the Order. It gives a new perspective on the world of D Gray - Man.
Another place to check is FanFiction.net. There are a lot of D Gray - Man fanfics there as well. However, the quality can vary more compared to AO3. You might need to sift through some to find the really good 'critical point d gray man fanfic' you're looking for.
Definitely. It should be a continuation. Since there are still so many loose ends in the original story, like the full story behind Allen's transformation and the ultimate fate of the Black Order. 'D Gray - Man Remaining Story' will most likely carry on the story to answer these questions.
In D.Gray - Man fanfics, amnesia can be portrayed in various ways. Sometimes it's used as a plot device to create mystery. For example, a character might forget their past and their powers, leading other characters to search for the cause. This can add an element of suspense to the story.
One idea could be a story where Mana and the Earl have to team up against a common enemy that threatens their existence in ways they haven't faced before. This would force them to put aside their differences and use their combined powers.
In some fanfics, Allen might be depicted as dead, but it really depends on the specific plot and the author's creativity. Fanfic writers often take liberties with the original story, so there could be various interpretations.
The D'Gray Man manga has indeed finished. It wrapped up with a satisfying ending that tied up most of the plotlines and left a lasting impression on readers.