Man are elusive; they hide their knowledge behind codexes and cyphers. To translate these is to foster knowledge and power. To do so, you must first find their physical selves.
This is not so simple, for the gateways to their lands have long since closed, and divvied themselves to the strands of Caelum.
The failures of your lessers, however, will prove a boon. Through studying the demise of those before you, you will learn to forge a way to Caelum.
Additionally, Man are technophilic; they manifest their work through interwoven crafts. With this, they forge opposing societies of immeasurable strength, and rule with armies fed by and armed with crafts. Technology and war share a purpose as the lifeline of Man.
Man are technologically advantageous; thus, dangerous.
Their warcraft is the power you seek.