I think I got the best ending for Sultan but I like dunno how to get images 1, 3 and 4, but yeah this vn is like amazing didn't really expect the direction
Perhaps the ending you've got is the neutral ending, in which Sultan lets you go without knowing the true murderer and does not see any potential relationship between him and Rayne. Btw the card that he gives is NOT Sultan's farewell gift. Sultan's chapter has 4 endings in general, you can keep trying to get the other endings!