I just did.
The first few times I invaded the same guy who one hit killed me with Homing Soul Arrow.
Then I was summoned to be the world 3-3 boss. That was pretty cool. It felt a bit like cheating though. I got a huge health bar, and I could heal myself just fine. It ended up being a good fight, with me mostly chasing after him. Using the Uchigatana wasn't working, he could block it quite easily. So I switched to 2-handing the Demonbrandt to guard break him. That worked, and I won. I got the Monk's Head Collar out of it.
Knowing you're doing this to some poor guy who probably doesn't know what to expect makes it all the sweeter.
Then I was summoned to be the world 3-3 boss. That was pretty cool. It felt a bit like cheating though. I got a huge health bar, and I could heal myself just fine. It ended up being a good fight, with me mostly chasing after him. Using the Uchigatana wasn't working, he could block it quite easily. So I switched to 2-handing the Demonbrandt to guard break him. That worked, and I won. I got the Monk's Head Collar out of it.
Knowing you're doing this to some poor guy who probably doesn't know what to expect makes it all the sweeter.