According to the "Star Wars Character Encyclopedia," Yaddle, Yoda's female counterpart on the Jedi High Council, is one of the sole Jedi to have learned the technique of morichro.

As can be surmised from its naming, the technique can be quite easily used to kill opponents altogether and it's generally considered a forbidden tactic among Jedi.

Despite Yaddle being confirmed to have learned the deadly art of morichro, she has never been shown actually using it — in canon, "Star Wars Legends" material, or otherwise.