Complex sentence: Mal made appearances in the two season show "Young Justice", Mal was shown to be the Boyfriend and later Fiancé of Bumblebee, Mal took the identity of Guardian (after Jim Harper) in order to protect The Hall Of Justice from an attack.
Split into simpler sentences: Mal made appearances in the two season show "Young Justice". He took the identity of Guardian (after Jim Harper) in order to protect The Hall Of Justice from an attack.