'DarthKnight'....... these challenges are 'Logic Puzzles' and as such only one jetpunker can be first to get the answer which is posted in the comments section. (see Challenges 1 to 69)
'overtired' you have done it again!...... quite correct of course 'H' is the next letter being 'Harmonia' the daughter of Ares and Aphrodite and sibling of Anteros, Eros, Deimos and Phobos............. your 12th Honorary Gold Medal is well deserved and on it's way :o)