The Rampage is an event occurring in the Heavy Fortifications close to the Kamura Village every 50 years. During this event, hordes of monsters march through the Heavy Fortifications and towards Kamura Village, threatening to destroy anything and everything in their path. The screech was from an Crimson Glow Valstrax serves an a warning for Rampage other powerful monsters and elder dragons showing up.
For a time it was believed that Magnamalo was behind the Rampage due to it showing up at the battlement of old Kamura village, wreaking havoc and caused the old Kamura to be destroyed. However, 50 years later, it was discovered that the true source were a pair of Elder Dragons, the Twin Serpents, Ibushi and Narwa.
It is revealed that, the rampaging monsters and Apexes were actually fleeing from the storms created by Ibushi and Narwa. Thus, they are willing to destroy anything in their way in order to escape. The Rampage was put to an end once and for all after Narwa the Allmother has been slain. Another Narwa the Allmother was discovered by Elgado Outpost, thus the Fierce Flame was sent to hunt it and successfully prevent the Rampage from returning.