D0 has 1 end, D1 has 5 endings, D2 has 5 endings, and the end of the first game has 1 ending with small variations.
however, the end of the whole series itself will include a few routes- one true ending, one dark ending, and one secret ending that's an offshoot from the true ending. if you want to pursue the darker ending, I can share how over discord, but it'll be a while till we get there.