Matters are coming to a head in a promo for the season one finale of "Legion" next week, as David (Dan Stevens) faces what is billed "his biggest challenge yet."

Presumably that challenge will involve facing down the Shadow King, the malevolent presence that has lived inside David's mind since childhood. In the show, that presence has taken many forms, with the most engaging version, Lenny Busker, brought to life with relish by "Parks and Recreation" alum Aubery Plaza.

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Throughout most of the promo we see David is still wearing the gizmo created by his friend Cary (Bill Irwin) to keep the Shadow King at bay, but it doesn't seem to be dampening David's powers at all -- he's able to literally sweep aside dozens of Division 3 troops with ease. As Dr. Melanie Bird (Jean Smart) puts it, David's powers make him a "world breaker," but will they also enable him to take on the Shadow King and emerge victorious?

We know that the "X-Men"-themed FX show has already been picked up for a second season, so that result at least already seems somewhat assured, but whether or not victory will mean the end for Plaza's character on the show remains unclear.

Either way, "Legion's" fist season finale looks set to give fans a memorable showdown between David and the entity that has been his lifelong nemesis.

Airing Wednesdays at 10 p.m. ET/PT on FX, “Legion” stars Dan Stevens, Rachel Keller, Aubrey Plaza, Bill Irwin, Jeremie Harris, Amber Midthunder, Katie Aselton and Jean Smart.