You get an eevee from bill in goldenrod city and train it till it evolves.
Umbreon Houndour Houndoom
You cannot catch an umbreon. The only way to get one is by training an Eevee at nighttime
To make Eevee evolve into an Umbreon, you have to level it up with high happiness at night.
You can't catch Rotom in heartgold.
you can't, you have to max out eevee's happiness at night to evolve it into Umbreon.
you cant catch him in heartgold you can only get him in soulsilver
In HeartGold you can catch Kyogre.
You can only catch Vulpix in SoulSilver, not in HeartGold. You can catch it on route 36 and route 37.
No
In pokemon Heartgold
Level it up at night whilst it has high happiness.
you cant catch it it is rare