Although Julius himself had given Spike a threat which meant that he planned on actually doing significant damage to him, Spike had no choice but to ignore Julius' warns as he didn't have a choice in the matter. Due to him still being under the control of Henry, Spike would have to forcibly walk into a situation where his death was guaranteed.
"I see, so you're not willing to back up huh? That's fine then, I'll just finish this battle off before it can go any further. Don't worry though, I'll be regenerating your body back to full health once this war has come to a close," said Julius as he began to slowly and seamlessly break multiple bones in Spike's body. One by one, Julius broke as many bones as he could find while moving around like a slithery snake.
After having nearly all his bones broken by Julius himself, Spike had no option but to sit down in a agony as he couldn't even cry due to him being under the complete control of Henry.