So, I can make a legit level 100 Pokémon that I can catch on FireRed, LeafGreen or Emerald, using rare candies and vitamins. It won't take me more than a few hours - a day to do one or two. I'd prefer an Arceus for each (or an arceus for 2, it all depends) but looking at all offers. FCs are in my siggy. (Most likely trading from Diamond.)

I also have some event pokémon. I will trade any of mine for a legit Arceus. (I'm a collector.)

UT Events:

TRU Regigigas
Jirachi (x3)
Pichu (x3)
Darkrai
Mew (unsure what event it's from, but it's caught in a cherish ball)

Unlegit legendaries (lv 51):

Lugia
Ho-Oh
Mew (x2)
Entei
Suicune
Raikou
Celebi (lv 3)

Shinies:

Lv 100 charizard? (Japanese-named)
Lv 50 Feebas
Lv 36 Mew

Not sure if the shinies are legit, got them off the GTS.

I am in DIRE need of a level 100 Zangoose ASAP! I'm supposed to get one to trade for an Arceus by this weekend!

I can trade you a lv 17 Zangoose since you can level it up with all those rare candies anyway. If you want it I'll take your feebas in return