Build up a massive army of elves, men and other nice people, invade Barad-Dur and set a dog on him 'just like old times'.
Tell him Luthien is better than him.
Tell him Felagund nearly beat him at singing.
Laugh at his singing.
STOP HIM SINGING.
Tell him that even if Minas Tirith had been invaded and there was a second Dark Years that Eru would have put a foot in and sunk the party anyway.
Tell him his old vampire suit makes his rear end look big.
Listen to him say his eye is superior to all attack and sees all, then get a mate and sneak up on him from behind and front simultaneously.
Tell him that he has the worst army in Battle For Middle Earth 2.
Tell him Saruman's orcs are bigger, smarter and have more dynamite.
Inform him of the fact he was beaten by a dog OVER AND OVER AND OVER.
Then inform him of the fact he was beaten by a midget.
... And his chief servant was beaten by a girl.
Tell him Aragorn looks more manly than him.
Ask whether wearing a big black helmet hides his pimples.
Enlighten him upon Olay Ultra-Clear. (the spot is gone in 24 hours!)
Tell him Artemis Fowl is WAY smarter than him.
Then prove it in a game of cross-book correspondence chess.
Ask whether he is really a HE.
...Run away from her.
Aaaaaah, cynicality.