Suggestions by @jonste101

Alfred Molina

as Horace Slughorn in Potter Boy(story private)

Score: +1

Andrew Scott

as Quirinus Quirrell in Potter Boy(story private)

Score: +1

Antony Starr

as Gilderoy Lockhart in Potter Boy(story private)

Score: -1

Florence Pugh

as Nymphadora Tonks in Potter Boy(story private)

Score: +1

Sean Bean

as Alastor Moody in Potter Boy(story private)

Score: +1

Olivia Coleman

as Dolores Umbridge in Potter Boy(story private)

Score: -1

Rory Kinnear

as Cornelius Fudge in Potter Boy(story private)

Score: +1

Annabelle Wallis

as Narcissa Malfoy in Potter Boy(story private)

Score: +1

Matt Smith

as Lucius Malfoy in Potter Boy(story private)

Score: +1

Alex Kingston

as Molly Weasley in Potter Boy(story private)

Score: +1

Stephen Merchant

as Arthur Weasley in Potter Boy(story private)

Score: +1

Mark Addy

as Vernon Dursley in Potter Boy(story private)

Score: +1

Eva Green

as Bellatrix LeStrange in Potter Boy(story private)

Score: +1

Paul Dano

as Peter Pettigrew in Potter Boy(story private)

Score: +1

James McAvoy

as Remus Lupin in Potter Boy(story private)

Score: +1

Kit Harington

as Sirius Black in Potter Boy(story private)

Score: +1

Emma Thompson

as Minerva McGonagall in Potter Boy(story private)

Score: +1

Nick Frost

as Rubeus Hagrid in Potter Boy(story private)

Score: +1

Nicholas Hoult

as Severus Snape in Potter Boy(story private)

Score: +1

Cillian Murphy

as Lord Voldemort in Potter Boy(story private)

Score: +1