While this seems rather unintuitive, since Overkill will kill the creature you target, this wont cause Jaws of Defeats trigger to fizzle
Also, a card like Mister Negative can have you swap life totals with an opponent, so if you push too far with your deductions, swapping life with another player is a great workaround
I suspect that'll be the case with Feed the Swarm as well as this will happen more and more and then you'll have better removal than this
Fen Stalker Fleshformer Frightcrawler Frightshroud Courier Gluttonous Zombie Gravelgill Duo Greater Morphling Guiltfeeder Hired Muscle Hired Muscle Hooded Kavu Inkfathom Witch Intimidation Jhessian Zombies Kami of the Waning Moon Lightning Reaver Lingering Tormentor Marrow-Gnawer Marsh Lurker Mask of Riddles Nezumi Cutthroat Nihilith Oddric, Lunar Marquis (playtest) Order of Yawgmoth Painwracker Oni
With Trample, you are guaranteed to spill damage over to the player, generating a hoard of gold in the process
Machina Citadel leads the charge with a massive 3000 ATK and a Quick Effect that can decimate your opponents monsters by turning a Machine you control into an explosion of shrapnel