Poseidon Card

Child of the Titans Cronus and Rhea and brother of Zeus and Hades, Poseidon was the Greek god of the sea, earthquakes and horses. Mythology depicts him as being a temperamental god, who often plagued those who angered him with storms and shipwrecks. His precise powers and weaknesses depend on the particular story in which he appears, but like the other Greek gods, very little can harm him. His only real weaknesses lie in tricking or deceiving him, and woe betide the trickster if Poseidon ever learns that he's been duped (Robert Vaux).

Strengths:

As the god of the sea, Poseidon has power over all forms of water, as well as the creatures of the sea such as fish and dolphins.  He carries a giant trident, which is so powerful that it can shake the earth.  His powers can be used to cause tempests and earthquakes, drown lands, shatter rocks.  He could call up storms and typhoons out of blue skies, drive ships into rocks with terrible waves, and create new land formations by unleashing great earthquakes.

In addition to oceans and earthquakes, Poseidon was the god of horses, and held influence over all things equine. He rode across the sea on a golden chariot drawn by hippocampi (aquatic horses), and myths tell of him fathering numerous magical horses.

Weaknesses:

As a god, Poseidon possessed very few tangible weaknesses. The most prominent was his comparatively limited influence. He had no power over the air or land (besides being able to cause earthquakes), and if he intruded into those realms, it would draw the ire of whatever other god held sway there. The best way to protect oneself from his wrath was simply to stay away from the ocean.

Like all Greek gods, Poseidon was petty, given to fits of temper and capricious whims which left no room for the opinions of others. While it made for quite a pinch if you were his target, it also meant that he could be distracted fairly easily.