The path to power is not complicated, when you are immortal. However just as simple is the slow decline into irrelevance and decay. Although time *may* be limitless, every moment of every day is vital. Sometimes the smallest increase in favors and energy is worth snatching at, other times you need to lay in wait for months, years, or decades for a monumental increase.

But that is obvious. The less obvious thing to keep in mind is that you must always, and only, be true to yourself. A million masks can and must be available to use at your discretion, but always know your goal. Your "Self".

And this Self is to be valued above all else. You may have friends, those you love, things and demons, that are dear to you. If they are ever more vital than the Self, than you will never gain true power. 

Sacrifice all at the altar of Self.

-Personal mantra of the Demon Master Bael.