New and returning faces appeared during Aztec Warfare.
On the first episode of season four, Antonio Cueto interrupted the memorial for his deceased son Dario Cueto to make some announcements. First was that Pentagon Jr would be defending his Lucha Underground Championship in Aztec Warfare in the first match of the season. Twenty wrestlers would be competing at timed intervals and the wrestler who does not get eliminated would be champion. Cueto says the Trios Champions will be the first three wrestlers in the ring for the match.
Only two of the Trios Champions in The Mack and Killshot showed up in the ring which prompted Cueto to say the next wrestler to enter the match will automatically become the third member of the Trios Championship team. That wrestler was Son of Havoc.
During Aztec Warfare, there were two debuts and two returns. For the first time, ECW legend Tommy Dreamer entered the match at number 7 and competed at Lucha Underground. Former Impact Wrestling roster member Jessie Godderz debuted at Lucha Underground at number 5 under the name Mr Pectacular.
Chavo Guerrero Jr returned to the Temple after losing a Loser Leaves Lucha match against Rey Mysterio Jr in the first half of season 3. Hernandez also appeared and had not been in a Lucha Underground match since the season one finale and both wrestlers were part of the Aztec Warfare match.
Fightful Wrestling had results for the Lucha Underground season four premiere.