Is there a way to invade other worlds apart from the cracked red orbs? Or is there anywhere to farm for them?
Also, I invaded a world once, fought someone, think I lost and went on my way. About 5 minutes later I was pulled back into their world without using any items to fight again. This just a weird glitch?
At least half a dozen ways.
There are red eye orbs (that aren't cracked) which allow you to invade permanently.
Theres a number of different ways depending on your clan.