Ok find an animated gif of the pokemon you want, copy the url of the image, and in your signature put IMG in [] and the url and end it with [/] with IMG in the last brackets too
By the way, I see you're asking for advice for online battles. I'm up for a match when you're free, but I suggest you first know about EV training and IV breeding though. Oh, and natures as well. Those are essential for having a good competitive PKMN. But my knowledge on competitive play only revolves around the 'mons I like to use and the foes I've faced before, so I can't really help with movesets and items of choice and other stuff like that. :/
Anyway, see ya later! I'm about to leave the office. :3
(Oh, and I read that you're looking for a Darkrai. I can give you one if you want. :3)
Your 6pm is 2am my time, so I'll still be drooling in my sleep at that hour. xD
But I usually wake up at around 9:30pm to 11pm your time (that's 5:30am to 7:30am my time), so we'll be able to trade at that hour. :3
I can give you a shiny Arceus. But I can trade with you later when I get back home, which will be 4 hours from the time of this post of mine. Will you be available by then?