That is impossible.....
!!
you cant do that in pearl but in platinum
Statistically, Mewtwo, Ho-Oh, and Lugia are tied as the strongest pokemon when based on stats.
get pokesav at pokesav.org
pokerus is a virus thank is good for pokemon. it raises stats and hp.
Nature will be displayed in the Pokemon Stats, you cannot find out before you catch it.
Use action replay.
In terms of stats: Entei HP Ho-Oh Atk Lugia Def Mewtwo Spd Mewtwo Spl Atk Lugia Spl Def. I would recommend either Mewtwo or Lugia based on those stats, but Mewtwo is incredibly late in the game compared to Lugia in SoulSilver.
Lugia, Ho-oh, and Rayquaza for legendaries. Then for pseudo legendary Pokemon you have Dragonite and Salamence. Then for "normal" Pokemon Togekiss.
Other than Lugia, I recommend using Dragonite, Metagross, or Tyranitar due to high stats.
You give it to Arceus to change its stats and type.
trade lugia to leafgreen and give it the blackglasses while in leafgreen and when you import when you recatch it [it must be imported with moltres articuno zapdos ho-oh and mewtwo to become shadow lugia while holding blackglasses and being imported]it will show up looking like shadow lugia[it will have awesome stats] have fun