(7/23/2021) If the spell that causes the last ability to trigger is countered or is otherwise no longer on the stack as the ability resolves, it will still deal damage
In the current format, there are numerous ways to return Pokmon to the hand, and this is usually a great way to remove damage from the board and stop the opponent from taking prize cards

Example Lists Mono Green Creature Based 24 Spells Llanowar Elves Fyndhorn Elves Elvish Mystic Joraga Treespeaker Noble Hierarch Skullclamp Rofellos, Llanowar Emissary Lotus Cobra Devoted Druid Explore Sylvan Advocate Satyr Wayfinder Tireless Tracker Rishkar, Peema Renegade Yavimaya Dryad Oracle of Mul Daya Garruk Wildspeaker Nissa, Worldwaker Verdurous Gearhulk Primeval Titan Walking Ballista Hornet Queen Crafterhoof Behemoth Decimator of Provinces 16 Lands Gaea's Cradle Treetop Village Rishadan Port 13 Forests Gr Ramp 23 Spells Search for Tomorrow Birds of Paradise Oath of Nissa Joraga Tree Speaker Arbor Elf Explore Sakura Tribe Elder Nature's Lore Sylvan Library Sylvan Caryatid Yavimaya Dryad Nissa, the Vastwood Seer Courser of Kruphix Den Protector Oracle of Mul Daya Polukranos, World Eater Garruk Relentless Nissa, Vital Force Primeval Titan Dragonlord Atarka Avenger of Zendikar Ugin, the Spirit Dragon 17 Lands Nykthos, Shrine to Nyx Myriad Landscape Kessig Wolf Run Tiaga Wooded Foothills Stomping Ground Raging Ravine Temple of Abandon 9 Forests These are just two fairly standard example lists

The game itself is pretty complicated
If "Dark Realm Gutless Zombie" is used to synchro summon a monster while equipped with a monster, return the monster in DEF position
Combustible Gearhulk is particularly sweet with cards like Wretched Gryff and Elder Deep-Fiend