Complex sentence: After taking out the emplacements, he was knocked to the ground twice by exploding enemy grenades, nevertheless, he got up and attacked three more times, each time destroying an enemy emplacement until he was wounded.
Split into simpler sentences: After taking out the emplacements, he was knocked to the ground twice by exploding enemy grenades. Nevertheless, he got up and attacked three more times, each time destroying an enemy emplacement until he was wounded.