Find the missing character?

Converting each letter to its numerical value, and reading pairs of circles as 2 digit numbers, arranged in two vertical columns, numbers follow the sequence of multiples of 7, starting with 14 and ending with 63.

AD = 14
BA = 21
BH = 28
CE = 35
And,

DB = 42
DI = 49
EF = 56
So,

F? = 63
FC = 63. Missing Character = C.