Same way as always: Friendship.
Blissey evolves from Chansey in Pokemon Pearl. Blissey is an all female pokemon species with no male counterpart. Chansey can be caught on route 209 and 210.
You have to trade for Happiny holding an oval stone or go catch Chansey on route 209 and if you do one of those Happiny can evolve into Chansey who can evolve into Blissey or you can catch Chansey like I did and evolve it into Blissey.
you cant... you have to make chansey evolve with high friendship. you can find chansy on rout 209 in diamond, pearl, and platinum
No Pokemon exactly evolves with it.Happiny though evolves if give it the oval stone and raise it one level in the day time.After it evolves into chansey make it like you alot and it would evolve into blissey
happiny into chansey
You have to make it have very good happiness and if you feed it hp ups and special defense gummies it should evovle the next time it levels up but try not to let it die.
You have to use an Oval Stone on a Chansey.
In Pokémon Pearl, you can find a trainer with a Blissey in the Victory Road however additionally you could hatch the Egg that the Hiker in Hearthome City gave you, let it hold the item the Oval Stone and level it up during the day time and it'll evolve into a Chansey and then you could evolve your Chansey into a Blissey when it has maximum happiness, it'll evolve as soon as it reaches maximum happiness.
Happiny---->Chansey using the oval stone.
It's a held item that only allows Happiny to evolve into Chansey if you level it up during the daytime hours.
It will evolve a happiny to a chansey (but if you do that on Pokemon diamond or pearl i don't think you can get another happiny so beware!).
Happiny. make it Hold it then lvl it up in the morning (4am to 8am I think) This gets u Chansey. To make it the infinatly fat Blissey, Make it REALLY Happy and lvl it ( to make it happy, win battles, don't let it faint and give it some medicine(Iron, Carbos etc.