The card text is in Korean (Hangul), the print runs are aimed at players and collectors in Korea, but the set artwork and game mechanics usually match the equivalent Japanese or English sets
First, when Calamity enters the battlefield, Terror deals four damage to your opponent, then when Terror saddles Calamity, Calamity creates two token copies of Terror, dealing another 10 damage
Back in the day this was far less of a concern, and we saw some truly wacky designs as a result
Because Tayam Mills cards as part of the activation, it also helps stock your graveyard while setting up future recursion loops
Markers have been in the game since Alpha and have always been an evergreen mechanic
Of course, in Commander games starting at 40 life, being able to drop it onto the battlefield in the first turn is going to be a pretty massive advantage