Lol, lot's of Bakugan do that. It has to do with the fact that both parts connect to either the same clip or another clip that's attached to the first clip (like Shadow Vulcan). When you push in the second arm, it opens the clip, letting the first are open back up. Just hold it down and it will stay closed. Sirenoi, Tigrerra, and many others suffer from the same problem.
How much does it give to Haos? 'Cause if it's a certain HSP Serpanoid card, then I have a killer strategy for you if you have a B2 Haos Serpanoid 500g…
Dang, mine give 300 to Haos. Here's the strategy…The HSP character cards double the G-power, not the bonus. So my B2 Haos Serpanoid would get it's Gs doubled to 1000. Plus the extra 300, and if my opponent uses a 700g or higher Bakugan, I can get an extra 400 from Shiny Devil, putting it at 1700g.