hmmmm well I have all the arceus cards and their LX. too and in the game I have arceus but my fav is mewtwo hmmm and I have every legend IN SHINY FORM (do not ask me for trade of shiny legends it took me one year to get them) so I guess you can just pick witch of mine is the most epic if you ask me its mewtwo or Arceus
My most epic Pokemon I've trained with is Kenya (Fearow.) She's named Kenya because I traded her. Kenya like the best--I trained her from about lvl. 25 to lvl. 80 without any rare candies!
Well, Suicune's my favorite, but it's hard to find a good one.
However, my Jolteon is amazing. Has a 31 special attack IV, 30 in speed, and timid nature. >w<
And fully EV-trained in both.