There were many traps along the way. Wires tripped by Kayneth's defenseless feet, or a fuse in the carpet that when stepped on would cause a pre-set grenade to explode or a mine to throw out shrapnel. At those times, the mercury protective membrane would expand immediately and rush forward to block it.

Those set traps were like toys made to fool children, so ridiculous that Kayneth wanted to laugh. But the sound of his laughter was at the same time mocking Kayneth, who was hurt by those tricks that were like toys made to fool children.

Self-mockery cut into pride like a razor. That humiliation inflamed the anger in his heart even more.

- Fate/Zero: Act 7, Part 3