Every time I go back to 'Bleach', the moment Zangetsu says 'protect Ichigo' hits different. It's not some flowery oath, it's a command, a fact. That's his entire purpose, born from the blade. The loyalty isn't chosen; it's intrinsic, the steel and soul of him. The strength part is trickier because he's so often mocking Ichigo's weakness, pushing him toward a colder, more brutal power. But that push is the strength. He's not a gentle mentor; he's the whetstone.
I keep thinking about the quote when Ichigo faces Kenpachi, and Zangetsu basically tells him to stop hesitating and crush everything. 'If you swing that sword only to protect, then slaughter everything that threatens your peace of mind.' It's a vicious kind of loyalty—protective to the point of annihilation. The strength he offers is absolute, merciless, and completely unwavering. It's not about being the good guy; it's about being the unstoppable force for your one person. That's a darker, more fascinating take on the theme for me.