Three Kingdoms: A Bronze Mirror Dimension, Where I Watch Zhang Fei Fight a Tiger from the Start

A cut on his hand from an old bronze mirror opens a portal that lets him travel back and forth. Armed with a crossbow and realgar wine, he ventures into another world and encounters a burly man who kills a tiger with his bare hands. The man says his name is Zhang Fei. Is this the Three Kingdoms? I can return through the other side of the mirror, but first I need to find out just how big the world beyond the portal is.