Step by step, create a new one.
shills will use misspellings, foreign characters, 1337, etc.
pleadians, pleiadians, pleaidians, etc.
([AEaeiǝ34]{1,3}) - 1-3 "vowels"
([AEaeiǝ34]{1,2}) - 1-2 "vowels"
pl([AEaeiǝ34]{1,3})d(AEaeiǝ34{1,2})ns
[Ss5]? possibly plural
test it on a regex page to find oopses