to get entei in crystal you need to prepare and you could find him
yes, after you beat the pokemon league if they are on a swarm.
in some cave
Crystal is a GEN:2 game while Latios is a GEN:3 pokemon. (so no)
You can't catch Mewtwo on XD, Colosseum, Ruby, Sapphire or Emerald. Mewtwo can be caught in the Fire Red or Leaf Green Version then traded over to Emerald, Ruby, Sapphire, Colosseum or XD.
From the sprout tower at night.
Yes
Any pokéball
no
entai- legendary dog Pokemon
You have to use palpark from a GBA game(pokemon)
no like in Pokemon gold,silver,and crystal version.
you catch it by chasing it use block or meanlook if it don't run attack it then thry throwing the pokeballs you have
After you go to burned tower it will appear in the wild randomly. how you catch it is up to you (personally I would use a master ball)
it is impossible without using the download from other games thing
start with bulbasaur an finish the game (includeing n dex) and done
for entai and raikou they are special random encountors suicoon is a sidequest
you need to start out with bulbasaur at the start of the game, beat the game, get the rainbow pass, encounter then track entei then try to catch it.