Response from LEGO SHOP
8 May 2019
Keith, Customer Service
Hi there, thanks for your review. I'm sorry to hear that you're having some trouble keeping the Oni Titan stable. We always test and retest our toys to make sure that they’ll hold up to play when they’re built exactly as shown in the building instructions. If something ever seems like it's not very sturdy, the best thing to do is re-check your build. Sometimes there could be a piece just a little off from where it should be, which can cause things to fall apart. You’ll also want to make sure that all the pieces are pressed tightly together.
If you'd like some help troubleshooting the build, or if you find that any pieces aren't working as they should, please get in touch at LEGO.com/Service.