Dialga and palkia.Hope i helped(if u have diamond go celestic town go in longest house and talk lady and left, and for dialga get the master ball from veilstone Galactic HQ)
Pal Park after the two men are out of the way (they should be if you have the national pokedex)
well for the normal one Cynthia (sinnoh region champ) had two pokempon i needed to see and i think that's how you see every Pokemon but if that does not work try evolving Pokemon
The Pokemon that is number two in the National Pokedex is ivysaur.
Pokemon Platinum has two different Pokedexes: the Sinnoh dex and the National Pokedex. In the Sinnoh dex, #152 is Rotom. In the National Pokedex, it's Chikorita.
You have to buy two games and two Game Boys and a link cable and trade in between the games
you could look for it but is too hard, so you have to see all the Pokemon in your pokedex so you could upgrade to a national pokedex then go to the professor he should let you pick one Pokemon from the johto region it should be the first of meganium "chikorita" and two other Pokemon.
you have two transport it from Pokemon ranger. if you just want it on your pokedex then go to bucklots mansion. go to his room and you will see a book on the desk. read it and it will show you a photo of manaphy. then it will be on your pokedex. you can also trade it from Pokemon heart gold or Pokemon soul silver,or mystery gift.
You have to see every single Pokemon on your pokedex. So look in your pokedex, and if you see a ? in a spot where a Pokemon should be, then try to find that Pokemon. (when i first played this game, I had this same problem, because i never saw Uxie, the being of intellegence. Go to all three lakes and catch or defeat the Pokemon there, because this is most likely your problem.)
493 is only how many the pokedex says there are. But Pokemon like shellos there is two types but the pokedex only counts it as one. Arceus evolves into different types if you use a certain type of stone and the pokedex still only counts all those combinations as one. If you want to see it for yourself check out this website: http://www.serebii.net/diamondpearl/newpokes.shtml
The last two are Absol and Girantina. You can see Absol on your way to Snowpoint City. And you see Girantina at Speer Piller in the Distroison world. Hope this helps!
You go to the Pokemon mansion and the first door on the right go in talk to the two men then behind them there is a book and if you read that then you get manaphy added to the pokedex
You should say the Pokemon's numbers, otherwise nobody can tell which Pokemon are the "last two Pokemon". My friend hardly ever battled trainers, so his last Pokemon he had to see were a Wormadam and a Luminion. Actually, I might be taking your question the wrong way. If it will help...wait one second! I just checked my Dex, and it only has 150 pokes in it. No.149 is Dialga, and No.150 is Palkia. I know that in Platinium there are 151 pokes in the pokedex, so you might be thinking of the wrong game. I hope this helped, even though it probably didn't. Sorry. :(