These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Vorbis. He launched his counter-attack before he launched his attack. He sent a man to Ephebe to die to justify the attack, and had to kill him when all they did was mock him.
Lu Tze, who changed the history of Omnia with a compost heap, not sweeping a pile of sand, and a bucket of water.
Magnum Opus: This is often cited as Pratchett's best book.
Moral Event Horizon: Vorbis, being head of the Quisition, seems to have crossed this point well before the start of the book. The death of Brother Murduck happened quite a while ago, and his plan to get through the desert, clearly costing a lot of lives, was even before that.