Here are some phanfics that I recommend on Wattpad and Fanfiction.net. Most of these are E/C with some Erik/OC and Erik x reader. There is also a R/C phanfic on this list, too.
-The Phantom Ascending by @olivesky (Wattpad)
-A Phantom Christmas Carolby @CharlesToth (Wattpad)
-The Man Behind the Mask by @Christinedestler1 (Wattpad)
- Phantom of the Opera Text Messages by @TheMJ1955 (Wattpad)
-A True Angel by @TaylorisaPOTOFan (Wattpad)
-Pen A Pal by @LJangel527 (Wattpad)
-E/C One Shots by @nightmare_carousel (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡOpnRbb1W3A
90Please respect copyright.ＰＥＮＡＮＡSEWROzy1Oh
-The Man Behind the Monster by @lukesagoodboy (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡPSLdstyJwx
-The Phantom of my Heart by @butterflygurlll15
(Wattpad)
90Please respect copyright.ＰＥＮＡＮＡryePSC9Jy0
-My Angel by rororogers (Fanfiction.net)
90Please respect copyright.ＰＥＮＡＮＡtGNOdSep5B
-Her Story by GoldenLyre (Fanfiction.net)
90Please respect copyright.ＰＥＮＡＮＡQzSJSMs9ey
90Please respect copyright.ＰＥＮＡＮＡCgdaig0p8f
-How Phantom of the Opera Should Have Ended by @Funk As Puck (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡVYoIwt7gCO
90Please respect copyright.ＰＥＮＡＮＡexz4D8BD9m
90Please respect copyright.ＰＥＮＡＮＡ1ncWIMG1O4
-No Dreams In Her Heart But Dreams of Love by Christine de Nuit (Fanfiction.net)
90Please respect copyright.ＰＥＮＡＮＡIr2dWxD0dk
-POTO One Shots by @PhantomLover2000 (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡfUTVOKFDNh
90Please respect copyright.ＰＥＮＡＮＡZ4WSFrmApt
-Unexpected Life by @hannahdestler (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡUVWyBuw9fG
-Dreams Came True by @hannahdestler (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡCYymWPoSeS
-Happily Ever...Phantom? by @LoveQueenElsa (Wattpad)
-The Phantomous Tales of the Phantastic Phantom by @therealprimmadonna (Wattpad)
-Our Love Is Evergreen by @BrendaDaaeDestler (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡodi3DDFWLR
-Every Waking Moment by @ChristineDaae1881 (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡmLrFtl4IA7
-The Phantom of the Phantom of the Opera by @BrendaDaaeDestler & @EmmaMarchAdams (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡklphmGT1mW
-Hear My Voice by @TheSwedishSoprano (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡk8EEvKNPfq
-In Dreams She Came by @BrendaDaaeDestler & @EmmaMarchAdams (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡ0jjoUqEgTf
-Never Learn To Be Lonely by loveyou232 (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡPyhPdEgP09
-My Angel of Music by @Christine__Daae(Wattpad)
-The Man Behind the Monster by @Hawkfrostlover13
90Please respect copyright.ＰＥＮＡＮＡtgFhlp55Dm
-I Love You, My Angel by @ cornelia-phantom (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡ9H8Vqc0LMh
-Phantom Christmas Story by @Destler_Erik (Wattpad)
90Please respect copyright.ＰＥＮＡＮＡpmtab3n4PE
and then Add to home screen.