How do you get the guy in front of 5th Gym to out way Pokemon HeartGold?

It sounds like you're talking about the "Mysterious Figure" standing in front of the Goldenrod City Gym in Pokémon HeartGold. This character is actually a trainer who only appears at certain times.

Here's how to get him to appear and challenge him:

1. Obtain the Radio Tower Key: This key is obtained from the Radio Tower after you defeat the Team Rocket Grunts and Rocket Executive Proton.

2. Complete the Radio Tower: After getting the key, you need to go through the Radio Tower and defeat all Team Rocket members inside.

3. Speak to the Gym Leader: Once the Radio Tower is cleared, go back to the Goldenrod City Gym and speak to the Gym Leader (Whitney in this case).

4. The Mysterious Figure Appears: After speaking to the Gym Leader, the Mysterious Figure will appear in front of the Gym and challenge you to a battle.

Note: You can only battle the Mysterious Figure once per playthrough. After defeating him, he will disappear from his location.

Important: If you haven't completed the Radio Tower, the Mysterious Figure won't appear. Make sure you have completed the Radio Tower before trying to battle him.