Transmigrated as a Fierce Tiger, I Swore Brotherhood with Hero

After working himself to death, he reincarnates as a legendary tiger fated to be slain on a mountain pass. Instead of fighting, he saves the warrior sent to kill him, and the two become sworn brothers. Armed with modern knowledge, he sets out to rewrite his brother's tragic fate, dodging lethal conspiracies and refusing a corrupt court's pardon. But as a brutal war looms, can a beast with a human mind truly defy destiny and keep them both alive?