This is a very good card and only gets better the higher one's willpower stat. While it lacks attack bonuses, damage bonuses and further, requires exhausting to use, its best feature is that it uses a hand slot, instead of an arcane slot. While Wither has a similar function, it does compete with other spells for precious slots.
It is relatively inexpensive and ideal for fighting odd-number health enemies, when an early game Shrivelling or Azure Flame charge would either be overkill, or underkill. Saving a charge to finish off 1/3/5 health enemies will also extend the life of those spells.
It also allows evading, with one's willpower stat, ad infinitum. Great for mystics whose hands aren't already occupied by Trumpets, Statues, Stones or Flashlights. And as if all that wasn't enough, unlike the eldritch equivalents, this mundane weapon has no downsides for drawing special tokens. 5 will investigators like Dexter, Agnes and Akachi, often with further passive bonuses, will get a lot of mileage from this card as a backup weapon/evasion tool. And it doesn't use an arcane slot!