I didn't say you had to use Royal Guard and Nevan, I was pointing out that Nevan is LIKE Royal Guard.
You play defensively and get to a point where you can kill an enemy, or group of, very swiftly. Royal Guard is the same, you defend and then unleash, but you don't have to use both together.
I personally use Nevan and Swordmaster because the addition of a few close-range moves really extends the combo sets.