From left to right:
1st Row:
Lord Voldemort (Harry Potter)
Na'vi (Avatar)
Cloud Strife (Final Fantasy VII)
The Emperor (The Emperor's New Clothes)
Nekkid Moses (The Hebrew Bible and etc., sans clothing)

2nd Row:
Hidan (Naruto)
Genesis Rhapsodos (Final Fantasy VII)
(Inspired by) Anubis (Egyptian God)
Trafalgar Law (and Bepo) (One Piece, pre-time skip)
Trafalgar Law (One Piece, post-time skip)

3rd Row:
Loki (Norse mythology, Tom Hiddleston ver.)
Thor (Norse mythology, Th'oreal ver.)
King Henry V (Henry V, Tom Hiddleston ver.)
Zee Captain (Romantically Apocalyptic)
Castiel (Supernatural, Famine-affected ver., My Bloody Valentine)

4th Row:
Misha Collins (ALS Ice Bucket Challenge)
Misha Collins (Supernatural, Meta Misha, The French Mistake)
The Winter Soldier/James Buchanan "Bucky" Barnes (Captain America: The Winter Soldier)
Misha Collins (from his wedding vows renewal event at a grocery store)
Lucifer (The Bible, Christianity, etc., My ver.)

5th Row:
Severus Snape (Harry Potter)