Convergence (Disney: The Zodiac Legacy, Bk. 1)

For one thing, he feels lost in a place where people expect him to feel at home. For another, a lot of the cooler museum exhibits are empty. And, oh yeah - he stumbles upon ancient pools filled with powers connected to the Chinese Zodiac. And then there's the Vanguard, the corrupt organization in the middle of a dangerous ritual to harness those powers. 

After unknowingly receiving the powers of the Tiger, complete with super strength and killer reflexes, Steven finds himself joining a ragtag group bent on stopping the Vanguard. Steven may be a quick-thinking fourteen year-old who can punch through walls, but the might of the Vanguard is unlike anything the world has ever seen. Or so the Vanguard would like to think.