Pointed Discussion

Dogpile + Hostility = fun.

Goblin Assault+Mightstone+Dogpile=Good times.

How does this work well with Hostility?

Once you play this, your attackers are already declared (Or you get zero damage. You can't cast spells AS you are declaring attackers, only before or after). 3/1 with haste or not, those elementals will just go to waste and this will deal no damage (prevented by Hostility) without a second combat phase (in which case, you'd have probably done better with a simple Lightning bolt on your main phase).

Unless you mean defensively... scratch that, "you control". As far as I can tell, useless with Hostility on the field.

This + a whole bunch of kobolds, no one will expect it.

I see what Zageitz is getting at. If you have let's say 6 creatures attacking with Hostility on the field and you cast this spell you would do 6 damage to target player (one for each attacking creature), however Hostility prevents that damage and gives you 6x 3/1 token creatures instead. If you can manage to pull that off once more time you would gain 12x 3/1 tokens the next turn for a total of 24 attacking creatures the turn after (assuming nothing dies in the process). Who cares how much damage you didn't do because of Hostility! That kind of exponential creature growth over such a short period of time will be difficult for anyone to deal with.

my RW Myr deck can OHKO someone with this, and they don't even have to be the one I'm swinging at! 4/5 for being a great win-condition.

Hostility isn't useless with Dogpile, it still gives you your tokens, and you can attack with them next turn. Sort of defeats the purpose of having hasty tokens, though.

I prefer Nacatl War-Pride.