Theros - or, rather, Nyx, the pseudoplane hovering in its night sky - is known to be chock full of squabbling gods; fifteen of them, in fact. The five monocolor ones appeared in the first set of this block, and now it seems five of the two-color ones will be in each of Born of the Gods and Journey into Nyx. One of the enemy-color gods, and one of my favorites so far, is Iroas, whose card I'm definitely looking forward to opening in a booster of Born of the Gods or Journey into Nyx.
Iroas is best known as the patron of the Iroan Games, which are Theros's combative version of the Olympics. He's also the favorite god of Akros, the mountaintop polis resembling Sparta. Both of these things mean he's the god of the glorious side of battle - discipline and well-earned martial victory. He's worshiped at the Temple of Triumph, and has self-sacrificing followers: a Priest of Iroas's martyrdom can defeat the works of the other gods.
In appearance, Iroas is a faceless Centaur in a winged helmet, wielding a javelin and covered in elaborate armor. This seems a little odd as a choice of physical form for him - after all, the Centaurs of Theros are green and white, not red and white, though this may indicate that there will be a few red Centaurs in the coming sets.
His relationships with the other gods are something of a mystery at this point, save for one thing - he's the sworn enemy of his twin brother, Mogis, who is favored by the Minotaurs as well as some of the more bloody-minded Akroans.
Check back here for more information on the remaining gods of Theros block.