I’m a Thelemite, and we’re pretty big on the idea of willpower. The primary public ritual performed by the Ordo Templi Orientis includes the phrase:
“Unto them from whose eyes the veil of life hath fallen may there be granted the accomplishment of their true Wills; whether they will absorption in the Infinite, or to be united with their chosen and preferred, or to be in contemplation, or to be at peace, or to achieve the labour and heroism of incarnation on this planet or another, or in any Star, or aught else…”
Though other Thelemites have different opinions, I think we choose to incarnate, and may have some limited control over what happens next through the refinement of our consciousness. It’s similar to the Buddhist perspective, but with additional potential goals beyond escaping incarnation altogether.