I'm pretty sure they go away permanently if you kill ANY type of legendary pokemon. well when i killed tornadus a few days later it came back
Nothing, you just can't catch him.
it wil never come back...
if by deciples you mean legendarys then reshiram ans zekrom are in n's castle bugt if you kill them they are in dragonspiral tower, victini is an event, tornadus(black) and thundurus (white) is found at route 7 after beating all 8 gyms. Cobalion is in mistralton cave, virizion is in pinwheel forest and terrakion is in victory road. Landorus is in abundant shrine after beating N and Ghetsis and getting both thundurus and tornadus in one game (trade with someone or cheat). Kyurem is in giant chasm after beating n and Ghetsis.
Well technically, you can't KILL a Pokemon. You can just make it faint. When you make a legendary Pokemon faint, it will be gone until you start a new game.
I'm pretty sure they go away permanently if you kill ANY type of legendary pokemon. well when i killed tornadus a few days later it came back
HOW TO FIND TORNADUS: You find Tornadus in tall grass. you battle in tall grass at the same spot till it starts raining. battle in the same grass till you battle. it may take a few tries but you will battle him if it rains. i found him at route 6 or 4.if you do battle him and use a move or poke ball and it doesn't kill him/catch him he will run away. battle in the same spot if he does run away. WHAT TO DO TO BATTLE TORNADUS: Go to Mistralton City. Go up northeast to Route 7 and it should start raining. Then go to the walking thingy. go up 4. go left 8, go up 15. go right 8, then go on the next walking thingy. go up 7. go right 11. then go in front of the house and an old lady walks out and says something. She takes you inside her house. have the soup she offers you. then go outside. there will be a weird thing outside. That's Tornadus. When he flies away go in the grass and you will battle him. It may take a few tries. To get Tornadus, you have to have beaten the Pokemon league. In Pokemon Black you get Tornadus; in Pokemon White you get Thundurus. The same way. you get Landorus. When you have them both at a special place. make sure you have Thundurus and Tornadus in your party to get Landorus
If you killed Tornadus, you can either restart (it is always good to save before a legendary battle), or you can wait for it to respawn. In the case of Tornadus, it might just take going back to a town and then using soar again. Other people have reported that working. If it doesn't though, you can try beating the elite four again. That usually brings the hard legendaries back, if you killed them.
nothing
If you kill azlef, It will FNT. so... save while you are in the cave.
Nothing, you just can't catch him.
it wil never come back...
if by deciples you mean legendarys then reshiram ans zekrom are in n's castle bugt if you kill them they are in dragonspiral tower, victini is an event, tornadus(black) and thundurus (white) is found at route 7 after beating all 8 gyms. Cobalion is in mistralton cave, virizion is in pinwheel forest and terrakion is in victory road. Landorus is in abundant shrine after beating N and Ghetsis and getting both thundurus and tornadus in one game (trade with someone or cheat). Kyurem is in giant chasm after beating n and Ghetsis.
In platinum it would be better not to kill mesprit uxie and azelf, it would be better to catch them.
you dont!
u suck start over
Well technically, you can't KILL a Pokemon. You can just make it faint. When you make a legendary Pokemon faint, it will be gone until you start a new game.