In the Chinese version of the game, Xin Zhao's name is rendered as Zhao Xin (赵信), as Chinese names are written with their family name first. In Traditional Chinese and in Japanese, the name would be written as 趙信, while being pronounced as "Choushin" via on'yomi.
His name Xin (信) means "faith" or "trust" in Chinese.
"Zhao" in Chinese is a unique character, only usable as a last name. However, it is mainly due to being written in Simplified Chinese. The Traditional version of the character is written as 趙, which can also be used in Japanese, which literally means "nimble".
He shares the family name of Zhao Yun (赵云), a famous general during the Three Kingdoms Era and a friend of Liu Bei. Like Yun, he uses a spear as weapon.
He may also be named after Zhao Xin, a Han general.
Xin Zhao is the only champion that references Asian culture but does not belong to Ionia.
Xin Zhao's joke is a reference to the question, "What happens when an unstoppable force meets an immovable object?" This in turn is a reference to the Chinese word Maodun, 矛盾 (lit. spear and shield) which means "Contradiction".
Coincidentally, Richard Epcar, Xin Zhao's voice actor, has done a few roles in the Koei Warriors franchise, namely Shingen Takeda in the first Samurai Warriors game and its expansion, but more so Dong Zhuo ever since Dynasty Warriors 4.
He shares this theme with Jarvan IV and Tryndamere, with all three referenced characters being featured in the Koei Warriors franchise.