your opponent can Special Summon 1 monster from their GY
The specific rule for commander damage doesn't specify that an opponent's commander had to deal the damage, just that a specific commander needs to deal damage
In this case youll get the threat and turn it face down as a 2/2
What makes this card so lethal, though, is the fact that on every turn but yours, you can loan it out, ala Assault Suit, to wreak havoc on the rest of the table
Furthermore, unlike most cards, many variations of the artwork feature the Pokmon doing different day-to-day tasks
As a commander, Kefka can be ruthless, forcing your opponents to discard cards and sacrifice their permanents (whack a Tergrid in here to be extra mean)