User blog comment:Miskos3/Fairy Tail Chapter 379: Tartarus Arc, Part 3: Underworld King, Review/@comment-4449950-20140404073720/@comment-7418318-20140405082001

Yes I noticed what you were mistakenly refering to as a unison raid before, or I wouldn't have posted this sentence in my previous comment:

"It's only a Unison Raid when the magic of the participants is combined before the spell is fired, while combination attacks merge already fired spells, like the Wendy+Scorpio example you mentioned."

In other words the example you gave is NOT A UNISON RAID. It's a combination attack.

A Unison Raid is when the casters join the magic still in their bodies togther.

A combination attack is when two already cast spells join together. You example is very clearly the latter case.