Dodgy footwork there, matey
Di-Kadi Sundi was a Jedi whose dodgy footwork led to his lightsaber being confiscated. A strange time-space distortion sent him hurtling back in time and twisted him to the point of being unrecognisable, and he was incorporated into the Jedi Hierarchy of that era.
Due to his horrible injuries, he worked to perfect the Battle Meditation technique, which would aid his allies in battle since he could not fight himself. He taught this to one of his pupils, Bastila, which is why she was so important in the Rise of Trask Ulgo. However, by Guy's time, everyone knew Battle Meditation.
Di-Kadi was killed by Darth Malak during the Sith War, but an essence of his spirit survived in one of the Jedi Holocrons. Centuries later his brother, Ki-Adi Mundi, became a member of the Jedi Council and named a wing of the Jedi Temple in his honour.