The second one is charging hourly. We tend to prefer hourly fees on projects that are particularly open ended or very small scope. Our hourly rates are currently between $60 and $120 per hour depending on who is doing the work.
The word sonder exists, though. It means to probe, and in a more specific use, to test the depth of something. The word sound (as in the water feature) is a cognate, both related to the Old English sund meaning to swim, or the sea. I can't really think of an English equivalent that's specific beyond mere awareness.
So it's basically Dark Father. (Rolling Stone, June 2, 2005). Vader is the Dutch word for father (the Dutch word is instead pronounced fah-der), and the German word for father (Vater) is similar. However, in the earliest scripts for Star Wars, the name Darth Vader was given to a human Imperial general.