"Fine! Since you seem so fascinated with the idea, then I suppose I'd be forced to admit that there is no guarantee on the outcome one way or the other!"
"Ha!"
"But!" Lucy leaned in closer, finger jutted out towards him. "That also means that you can't discredit any of my good theories any more than I could discredit your bad theories!"
"As if! Humans are selfish by nature, and they can't be trusted to make good choices, even if it seems obvious!" That much he knew for a fact. "I can concede to your point that technically there is no way you can be entirely certain. However, I'd say I have a clear advantage in what seems more likely." He crossed his arms, "if things are just fine now, then you should just let them stay the same. If things still get screwed up, then it's fate, not on you to do anything about it."
"Gah! Things can't just stay the same forever! One day something's going to change, and you'll have regrets about it if you didn't act beforehand!"
"Oh?" He found himself slipping into an old voice, a voice that was the last thing more than a few people had heard. "Are you saying that it's better to regret your choices than your circumstances? Cursing your fate is easy. No one admits to their own mistakes and lives to enjoy it."
Cobra could faintly hear Lucy's heart accelerate, her breathing go slack as she gulped. But she didn't back down from his proclamation.