Likewise, it also works really well in counters decks (like my Hamza, Guardian of Arashin deck), as the cost to prevent your draw will increase as Esper Sentinel gets bigger and bigger, easily making it more costly to pay for than even Rhystic Study
Dire Fleet Poisoner The best black MTG pirates card
It's a popular and powerful effect, and one I expect Wizards to return to many times over the years
Speaking of big creatures, if you are the rare green deck that doesn't have any, Khalni Ambush drops from great to medium or even bad, but since big creatures are more or less green's thing, it's hard to imagine too many green decks that won't get value out of the instant-speed fight spell
The Swarmlord is a mix of two different mechanics, +1/+1 counters and death triggers