Zant drove him crazy, up a wall, through the ceiling and in the opposite direction, deep down into the crust of the planet all at the same time. How he was even capable of coherent thought was beyond Ghirahim, and it was a struggle with even attempting to put two and two together.
Zant was lucky enough that even half his unplanned, sloppy attacks hit anything, much less an enemy. What was wrong with him, Ghirahim could never quite figure out. The Twili was better off being their tactician than being someone on the front lines, better off coming up with the plans to take out which keep and what major enemies to target – but no, he had to remain in battle. Ganondorf had needed them to assist him and needed them to follow for as long as possible.
How peopple even found the Twili to be attractive enough was beyond him, and he'd settle for beings that looked akin to him, not like the half shadow beings the Twili were.
But Ghirahim and Zant shared something in common – they shared the fact they had been discarded as beings before, and he didn't know how to feel about that. He found the other man to be extremely problematic to their forces, and oh, how he was quite the brat.