Uechi Gothic by D. Rakowski is a free medieval initials font with a blackletter spirit and a flourish-heavy voice. The letters mix thorny Gothic shapes with curling, vine-like ornament, so the font feels half manuscript, half carved emblem, with decorated strokes doing most of the talking.
It sits naturally in book covers, fantasy branding, chapter openers, poster headlines, and title cards where a little heraldic drama helps. As a free font, it also suits monograms and short display lines, because the ornamental letters carry enough texture on their own and quickly turn a few characters into a period cue.