"I, I must succeed" are the infamous four words which V said to gain ultimate arcane power. But this is not about them. In Don't Split the Party, V has said four words on occasion. Two of these four word instances are important because not only do they reflect an important moment for V, they were both said to the right person for the wrong reasons. Here we are:
Disintegrate. Gust of Wind
These four words were said to Kubota (the right person as he was evil and needed to die). But they were said for the wrong reasons. V only blasted Kubota because Elan tied him up and because he threatened to stall the story. Elan's reaction to these four words causes V to leave OOTS in frustration.
My power...EXCEEDS yours!
These four words were said to Xykon (the right person as V intended to kill him). However, they were said for the wrong reasons as V was not more powerful than Xykon. The words caused Xykon to react by giving the hannibal lecture about how Power equals Power. This caused V to snap out of it and use hir powers constructively (Blackwing, Guess which spell I put on this before giving it to the bird), something still done to this day (Kobold Crossbow!!!).
Is this a coincidence? Yes. But it is a very clever one.