Complex sentence: His voice was weak when he said the Mass, and after the Mass had concluded, he was so weakened that he almost collapsed as he was descending the altar steps and needed help from a great many of his Capuchin confreres.
Split into simpler sentences: His voice was weak when he said the Mass and after the Mass had concluded, he was so weakened that he almost collapsed as he was descending the altar steps. He needed help from a great many of his Capuchin confreres.