Rearranging the letters of 'Anagram composer' (One who composes anagrams) gives:
So arrange, Mac, mop!
(by Kevin Sheldrick by hand) (2015) (pending approval)
Other related anagrams without their own page:
"What is an anagram" -> "A harming Satan. Aw!" (by Josiah Winslow) (2011) (pending approval)
"Severe anagram addict" -> "Advanced a grim teaser." (by Jim Banholzer) (2015) (pending approval)
"Why anagram addict?" -> "Magic handy at ward." (by Jim Banholzer) (2017) (pending approval)
"The most severe addiction to anagrams" -> "Hadn't vim to cease to disarrange tomes?" (by Mike Mesterton-Gibbons by hand) (2004)
"The most severe addiction to anagrams" -> "O, man! To read AG's archive doesn't stem it!" (by Mike Mesterton-Gibbons by hand) (2004)
"A manically presage William Shakespeare" -> "I am a especially weakish anagram speller." (by Jim Banholzer) (2018) (pending approval)
"Arif Fachrudin - Ponorogo - Jawa Timur - Indonesia" -> "Contoh anagram dia jadi isu ne WN RI or FPI or UFO." (by Arif Fachrudin by hand) (2011) (pending approval)
"Arif Fachrudin - Ponorogo - Jawa Timur - Indonesia" -> "Roso Jiwo Rogo Fidin Nur Fidihana nate pacarmu." (by Arif Fachrudin by hand) (2011) (pending approval)
"Anagram Genius Archive Main Index" -> "I am in an amusing, varied exchanger." (by Simon Robinson using Anagram Genius) (2005)
"Anagram Genius Book" -> "A mega-arousing knob." (by Joe Fathallah) (2004)
"Anagram Genius Book" -> "A knob-arousing game." (by Joe Fathallah) (2004)
"Anagram Genius - The Last Build" -> "Managing a ruse - Bullshit date!" (by Mark McNamara using Anagram Genius) (2008) (pending approval)