Sans is the laid back skeleton brother from Undertale, released in 2015, whose Genocide route boss fight became legendary for its speed, fake outs, and punishing patterns set to Megalovania. Clips explaining how the fight works spread through gaming and meme communities because the battle subverts normal turn based expectations, letting Sans dodge, attack first, and break the rules. Short edits like this one keep circulating as a shorthand for an unfair boss, a try hard challenge, and the shared memory of countless failed attempts.