AFFIXIT!

The city  is under threat from an evil alien who feeds on the jibberish that the planet's people speak.

If it is allowed to eat too much jibberish, it will be too late, it will be too strong and the world will be doomed.

Once mortal enemies, the wizards PREFIX and SUFFIX must join forces to turn the jibberish into real words which harm the jibberish loving alien.