Fantastic card. Great tribute fodder for pretty much anything you want to tribute. Use it with econ to tribute summon a monster and remove your opponent's monster in one go! Use order to charge on it. Having an easy special summon that works in any deck (that isn't a meta deck like red eyes) is vital. If you don't want to use meta decks you should put two in your deck. It can easily boost your win ratio.
I was having all kinds of trouble because my deck just wasn't capable of putting two monsters on the field in a turn. Decided to put two of these in and went on an instant win streak.
Yeah, not worth anyway. If it is for a mission, play with a friend and tell him/her to use Embodiment of Apophis, use Exchange card (from Joey drop) or use a card to get EoA out of the graveyard.
Most players underestimate this card quite a bit.
It has a good def, can be summoned instantly like a trap and is great for tribute fodder.
And it also has a good synergy with storm which is an awesome card.