Find the missing character?

J
O
T
V

The missing character is O.

The other characters in the sequence are A, E, I, O, U. These are the five vowels in the English alphabet.

The sequence is a list of vowels, with each vowel repeated once. The first vowel is A, the second vowel is E, the third vowel is I, the fourth vowel is O, and the fifth vowel is U.

The missing character is O, which is the fourth vowel in the English alphabet.