This quote powerfully illustrates the inherent danger of wielding something that is intrinsically harmful, regardless of the righteousness of the cause behind it. The metaphor of the weapon as poison transcends traditional ideas of physical harm and ventures into the domain of moral and psychological corruption. Kit's assertion that carrying the weapon is poisonous even if it doesn't immediately cause visible wounds invites a reflection on the burdens we accept and the toll they may exact over time. It suggests that some actions and decisions carry dangers that are not always obvious but manifest slowly and insidiously, eroding one's wellbeing from within.

Marcus’s reminder that it's "a sword"—seemingly ordinary but fundamentally deadly—underlines a universal truth: the tools we use, including those wielded for justice or defense, possess an intrinsic nature that can have unintended consequences. This duality captures the complexity of power and responsibility. Even when we believe our intentions are just, the implementation and the very possession of violence shape us in ways that can degrade or consume our spirit.

In a broader sense, this quote speaks to the compromises and consequences entwined with any form of struggle or conflict. It emphasizes the importance of awareness about not just external dangers but the internal transformation wrought by continual engagement with harmful means, no matter how noble the ends. It invites contemplation on how we must be vigilant about the costs of our actions, both visible and hidden, reminding us that some poison is elemental and inescapable.