See this is how I thought it worked all along. Invis out of the book is just too damn powerful

Q: How does the Invisibility psychic power work in relation to nova and beam powers, and Template
and Blast weapons not initially targeting the invisible unit?
A: You cannot choose to target an invisible unit with such attacks, but should models from the unit
end up beneath the template, marker or line of fire, then they can be hit using the normal rules. The
invisible unit would be hit if it was on the line of a beam, if it was in the range of a nova, or if a blast
ended up being scattered onto it. For Template weapons, as long as you follow the rules – ensuring
that the template ‘covers as many models in the target unit as possible, without touching any other
friendly units’ – then if the invisible unit was also fully or partially under the template, it would be hit.