Find the missing character?

A
M
P
V

The missing character is M.

The sequence is a series of letters, each of which is the next letter in the alphabet after the previous letter, except for every third letter, which is the letter M.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A B C D M E F G H I J K L M N O P Q R S T U V W X Y Z

A B C D M E F G H I J K L M N O P Q R S T U V W X Y Z

Therefore, the missing character is M.