Eliminating King Sage Cat

Hoh... Did you manage to find the antidote...? You weren't able to get one from King Sage Cat...? Isn't that obvious? If he was to give you the antidote that easily, then he wouldn't have poisoned me in the first place... Cough cough!

There's no other way now. You'll need to defeat King Sage Cat and obtain the Antidote Marble! I truly believe...

Hmmph... (breathing heavily)... oh, you, you are back... were you able to...oh, so this is the... Antidote Marble...

Cough cough cough!