Shinobi (2013)

From publisher blurb:

A covert agent or mercenary who specializes in commando-style operations, a shinobi is a professional spy, thief, saboteur, and assassin. Using a variety of unconventional weapons and her rigorous training in Ninjutsu, a shinobi can handle a large variety of tasks capably. While the shinobi and their techniques began among peasants forming a covert resistance to the oppressive warrior caste, in time those same skills were soon available for hire to the very same warlords. Demand for the covert operatives’ services grew, with the peasants using the wealth acquired to build their own family clans to pass on their secretive training and work together on larger missions.

It is impossible to say how many shinobi there are - a common saying is that “the best shinobi is the one that you never knew was even there.”

Role: Even among a group of fellow adventurers, a shinobi will tend to be secretive and will stay close to her cover identity as often as possible. She may even tend to act in more of a supporting capacity unless forced to direct action. Those who come to earn a shinobi’s trust, however, will rarely find a more formidable ally. By the same token, those who betray her will rarely see a more deadly enemy.

This is a 20-level base class.