Workhorse event. Pretty good in a large variety of decks.
First off, a singular 3 damage attack with high hit chance is perfectly presentable by itself. People play Backstab fairly regularly and Spectral Razor sure as hell blows that old thing out of the water in terms of price and hit chance. Most characters can mount a +7 or +8 bonus without any support from other cards, which is enough to net hits on medium and hard with relative ease, Backstab in comparison requires some skill card committal or other forms of boosting to land a secure hit.
The ability to blow away a 3-health foe completely free of any support from other cards is perfectly worth a card. It's frankly super impressive at 2 cost and 0 xp.
You can build a deck with 2 Shrivellings and 2 Spectral Razors and use the Razor to cover yourself while you wait to find or play a Shrivelling, alternatively you can play it with Wither and finish off a foe you've started working on. If you have all 3 cards in a deck you've got yourself a very powerful, and dependable, combat focused battle-mystic!
The free engagement is the cherry on top, pull an enemy off of a friend before striking (removing the friendly fire risk) or engage an aloof enemy who'dd otherwise cost you an extra action! Luke Robinson has confusing rules but this probably lets him teleport enemies around!
Obviously the card is uniquely useful in campaigns where 3-health foes are more common, Forgotten age and Circle Undone have these in abundance.
It's good to see more events that are good without heavy support or combo mechanics.