Every mode so far kept one thing sacred: a stable tonic triad. Locrian gives it up — flatten the 2 AND the 5, and home base is a diminished chord with a tritone where the anchor should be. That's why this card is honest with you: it's a color, not a home, because no song can rest on a chord that physically will not sit still (the famous exceptions are stunts, and they're famous BECAUSE they're stunts). But the pitch set earns its keep as the sound of the half-diminished chord — over any 1ø⁷ moment, Locrian is simply its notes. Darkest paint on the shelf; apply one bar at a time.
The b5 — the tonic's own fifth is diminished, so the chord you'd rest on can't hold your weight.
Your tonic is the 7 of the parent — the major key a half step up shares every note. B Locrian is C major's set standing on the one degree whose triad is diminished.
Don't force a tonic — a 1ø⁷ ↔ b2 vamp reads as tension aimed somewhere else, because it is. When you meet ø⁷ chords in the wild (the minor ii–V, the borrowed 2ø⁷), that's Locrian doing its actual job: a passageway, never a house.
Almost nowhere, honestly — Björk's 'Army of Me' bassline is the exhibit usually cited, and John Kirkpatrick's 'Dust to Dust' was written in it deliberately to prove a Locrian song could exist, which rather proves the point.