Complex sentence: After Matthew left XPW due to family issues, Luke began competing as a singles wrestler, and participated in the final King of the Deathmatch Tournament to determine the new King of the Deathmatch Champion.
Split into simpler sentences: After Matthew left XPW due to family issues, Luke was left on his own. As a singles wrestler, Luke took part in the final King of the Deathmatch Tournament to crown a new King of the Deathmatch Champion.