Ciphas does stangle. IIRC its a 7k damage on jump+2-3k each time. Needs to be interrupted asap. The RDPS in you raid should be doing this. As soon as he jumps, the RDPS all hit their interrupt(keybind it) there is no other way to circumvent this as melee might be out of range as he can jump to random people.
I've had problems hitting my interrupt as soon as he jumps, as it sometimes likes to go off before he starts casting due to a very slight delay. Still, works most of the time.