This card is a great example of Power creep, and why it prevents the use of newer cards.
This card is in direct competition to vicious blow, and begs the question "why would I ever use this over vicious blow?"
The short answer there is that you won't. Everyone that can take this card can also take vicious blow, and vicious blow outperforms this in all scenarios.
What about taking it AND vicious blow? I could see some use in the fighter style characters without access to the heavy hitting guardian weapons. Yorrick and Silas come to mind right away. But you still have to wait for this card to take effect, meaning the enemy will most likely get an attack off. This somewhat defeats the purpose of attacking the enemies then. Most enemies have 3 HP, and the ones that have more usually have 5-6. So you do a vicious blow augmented standard attack on a 5-6 HP enemy, and it lives and your turn ends. The enemy attacks you and then this ticks. So the enemy now has ~4 damage on them. This translates to you having to attack the enemy again your next turn to finish them off, or leaving them evaded for two turns someway to make this card eventually run its course. You very quickly then get into a Rube Goldberg style problem with "why didn't you just kill it with another attack", which begs the question again of why did you take this card.
So when do you use this card? The only reasonable excuse I could see would be on enemies with exactly 4 HP, using an investigator with smaller arms and probably that also has stunning blow and can outmove the hunter keyword.
It ends up being a lot of very specific criteria to make this card worthwhile, so I can't honestly say it has a place in any deck.
If future upgraded versions had a draw attached to it, we may be talking though.