Beware!

Ben, Gwen and Thanatos are fighting Black-Out. He teleports them to many places (possibly to avoid). Ben uses Swampflame and burns the Teleporter and caused them to plunge into Pacific Ocean. There Ben meets Phobus. Phobus questions Ben and Gwen why did they come. Thanatos thinks for a moment and realizes that he is in Phobus's pit of Violence. Ben asked Thanatos if this is his cousin but Thanatos explains that this is his nephew and how much trouble he causes. Then there are some flashbacks about Thanatos and Phobus such as Sinking of the titanic, breaking the sphinx's nose, burying the pyramids, accidentally stealing all the wealth in the pyramids, leaning Pisa and Sinking Atlantis. Before Ben could change, he fell asleep. Suddenly Gwen too fall asleep later, the duo find themselves in a desert.

Later, Gwen finds a huge spider which encloses the space. Gwen screams at all her might. Phobus, outside, was laughing and getting powerful due to fear. Ben then, uses the Omnitrix to change into something good but ends up Freezer. Unusually freezer has no more breath to fire and ends up unconscious while he gets into a pit of quicksand. He too screams making Phobus more powerful. Later, Thanatos appears and led Ben to have courage which he destroys the fears and saves Gwen. Gwen too got the courage and destroys the visions. Finally, Ben changes into Jetblast and confronts Phobus. But with the help of Stan Li and Tempeter, he banishes Phobus who changes into a dragon.

Aliens used
Gooey

Energybender

Swampflame

Freezer

Jetblast

Fire Lizard