Using magic, I've built a machine that instantly generates hash collisions. To try it out, I set the dial to SHA256 and typed in "e7cf3ef4f17c3999a94f2c6f612e8a888e5b1026878e4e19398b23bd38ec221a".
I hit the button and it showed me a long sequence of bytes starting with "09F7E02F1290BE211DA707A266F153B3...". I hit the button again and it showed me another long sequence of bytes starting with "F326BED0DD25CED6BC1799EAF74E7F8C...".
Every possible hash output has an infinite number of collisions. My machine is just picking one of those collisions at random.
What practical uses could I have for a machine like this? You can't reliably get a collision you want - such as one that starts with a given salt or is structured as a valid Bitcoin package - just one of the many random looking collisions.
Note that attempting to open the machine will cause it to disintegrate, leaving only a golden egg behind.