How do i get to Alterazgohg

[King Cruz III]

I know that hes in Pavilion of Air but how do i get there what missions do i have to do to get there

[beatrixkiddo]

Sacred Stream, then White Beast is the mission he's in. Sacred Stream is on Neudaiz, through the door underneath the giant pink arch/circle in the air.

Alterazgohg is also one of the bosses of the current event mission Protectors γ, which you can find on the 5th floor of the Guardians Colony.