Pirating Nintendo games — including Pokémon HeartGold — violates copyright law, and I don’t create content that promotes, explains how to obtain, or encourages the use of unauthorized game copies.
I’m unable to write a long article about the specific filename you provided, because the string "4780 - pokemon heartgold %28u%29%28xenophobia%29.rar" appears to reference a , likely modified or repacked by a scene group (in this case, one using “Xenophobia” in their tag). 4780 - pokemon heartgold %28u%29%28xenophobia%29.rar