• Kadabra --> Alakazam
• Machoke --> Machamp
• Graveller --> Golem
• Haunter --> Gengar
• Seadra (Dragon Scale) --> Kingdra
• Poliwhirl (King’s Rock) --> Politoed
• Slowpoke (King’s Rock) --> Slowking
• Onix (Metal Coat) --> Steelix
• Rhydon (Protector) --> Rhypieror
• Syther (Metal Coat) --> Scizor
• Electabuzz (Electirizer) --> Electivire
• Magmar (Magmarizer) --> Magmortar
• Porygon (Upgrade) --> Porygon 2
• Porygon 2 (Dubious Disc) --> Porygon-Z
• Duskull (Reaper Cloth) --> Dusknoir
• Clamperl (Deepsea Tooth) --> Huntail
• Clamperl (Deepsea Scale) --> Gorebyss

How to get rotom key

1. Obtain Rotom
2. Head to Jubilife City.
3. On the second floor of the Jubilife TV building, talk to the TV Producer to let him conduct an interview with you. He'll ask you two questions, requiring you to answer with two words for each one from the preset list of words in various categories (use ABC Mode to find them easier).
4. Answer the first question with EVERYONE HAPPY.
5. Answer the second question with WI-FI CONNECTION.

6. The Producer will comment that you know "inside information", and that his sources will have something special for you. This unlocks the Mystery Gift option on your main menu.
   

After April 20th and until May 12th....

1. Select Mystery Gift on the main menu, choose "Receive via Nintendo Wi-Fi Connection", and you'll receive a Secret Key for your Key Items.
2. Head to Eternia City and enter the Team Galactic Building.
3. On the first floor, in the upper-left corner of the room, you'll see two large electronic boxes and an empty wall to the left of them that looks "different". This is Team Galactic's Secret Room, inaccessible up until this point in all three games. Until now, that is.
4. The room will contain five appliances corresponding with the five types Rotom can 'assimilate': a Washing Machine (Water), a Refridgerator (Ice), a Fan (Flying), a Lawn Mower (Grass), and a Stove

You will need some hms as in rock climb,rock smash and strength.

1. You need to go deep into the Stark Mt, to find the magma stone.You will be with some one called Buck. Note the will be team galactic after the magmar stone.
2. Go out of the mt.
3. Go to the buck's house, and talk to him and his father.

4. Go again to the magma stone room. Heatran will have appeared.
   

To catch him:

1. Have about 30 dusk balls. Note you will not have to use all om the dusk balls. 
2. Get Heatran down to red hp by using rock smash on him and start throwing dusk balls.
3. This may take a long time it did for me

.Good Luck.

Magmortar

How to get:

Give a Magmar a magmarizer and trade it.

Steelix

How to get:

Give a metal coat to an Onix and trade it.

Dusknoir

How to get:

Give Dusclops a reaper cloth and trade it.

Likylicky

How to get:

Get a Lickitung to Level 34 and teach it rollout.

Starraptor

How to get:

Get a Staravia to level 34

Gengar

How to get:

Trade Haunter.

Aerodactyl

How to get:

Once you have the national pokedex go underground and mine. You might come across some old amber. Take it to the fossil reanimator guy.