Complex sentence: Out of options, Leonardo then faces off against Super Shredder in a one-on-one duel to the death; with him finally destroying Oroku Saki by running him through with his swords.
Split into simpler sentences: Out of options, Leonardo then faces off against Super Shredder in a one-on-one duel to the death. The battle ending with Leo finally killing Super Shredder by running him through with his swords.