Stela 31 is the accession monument of Siyaj Chan K 'awiil II , also bearing two portraits of his father , Yax Nuun Ayiin , as a youth dressed as a Teotihuacan warrior . He carries a spearthrower in one hand and bears a shield decorated with the face of Tlaloc , the Teotihuacan war god . In ancient times the sculpture was broken and the upper portion was moved to the summit of Temple 33 and ritually buried . Stela 31 has been described as the greatest Early Classic sculpture to survive at Tikal . A long hieroglyphic text is carved onto the back of the monument , the longest to survive from the Early Classic , which describes the arrival of Siyah K 'ak ' at El Peru and Tikal in January 378 . It was also the first stela at Tikal to be carved on all four faces .