Make the higher level as a CR 2 creature
You'll notice a few things after looking at monsters and stats for games, and this holds true for both DND and other roleplaying/video games.
Enemies have high health and accuracy, but low damage.
Players have low health and accuracy, but high damage.
This is for a few core reasons:
- Fights last longer than a few turns
- The high accuracy and low damage from monsters against low health players means that healing is impactful, without the risk of players dying being unable to react against threats
- Damage from players seems like they hit major organs, and feel much more dramatic, while still making the monster able to get hit a few times.
- Enemies are a constant threat, who's tough to take down without being frustrating.
If you've ever played an RPG video game, had one of your characters get confused, and hit one of your own players, you'll know exactly how devastating it can be.
On the same note, there's a reason you can't just let low levels take on a Rakshasa. They have inherent abilities that are supposed to be trumped by powers available at higher levels.
From my experience, PVP, especially with different levels, is not worth the hassle, and is fun for the last people standing, since everyone else died in the second round.
My recommendation is to avoid having the higher level player be a standard PC, and rather build him to be a CR 2 creature. That kind of fight would be designed for a group of 4 level 2 players, which would be a balanced fight for 6 level 1s, and handles the experience handout at the same time.