DESCRIPTION
"We asked two witches of different skill levels to make a blade out of magic and these were the results"
A "spirit blade" is any magical construct that's refined and sharpened enough to cleanly cut through a target. Maintaining even basic magical constructs without the use of a soul patch is considered advanced magic by conventional witches, and achieving that level of sharpness can take years of practice.
Witches who learned beyond the Veil, however, are typically not conventional in any way.
"I prefer to call it a spite blade, actually."