Zalgo
Ṫ͌ó̍ ̍͂̓̍̍̀i̊ͯ͒nͧ̍̓̃͋vok̂̓ͤ̓̂ěͬ ͆tͬ̐́̐͆h̒̏͌̓e͂ ̎̊h̽͆ͯ̄ͮi͊̂ͧͫ̇̃vͥͦ́ẻͤ-͒m̈́̀i̓ͮ͗̑͌̆̅n̓̓ͨd̊̑͛̔̚ ͨͮ̊̾rͪeͭͭ͑ͧ́͋p̈́̅̚rͧe̒̈̌s̍̽ͩ̓̇e͗n̏͊ͬͭtͨ͆ͤ̚iͪ͗̍n͐͒g̾ͦ̎ ͥ͌̽̊ͩͥ͗c̀ͬͣha̍̏̉ͪ̈̚o̊̏s̊̋̀̏̽̚.͒ͫ͛͛̎ͥ ̎Iͫ̅n͆̆͑vͦ̅ŏͩͧ̓̊̀ͩk̃ͦ̚ĭͥ̏̊͆̌̈́ńg̅ ̒̋t̽̔h͊ê͑ ͐͂̀̈feͮ̑͋̀ͦe̓l͒̚̚i͛̋̅̆ͮnͨ̿̌̄gͣ ̌̅́̈́ȍf̋̏ ̇ͩ̇ͧ̏cͭ̔ȟ̈́͆a͋os͗͑̈̐.̔ ̆̒ͮW̓͋ͮ͐̚i͂t̊ͪhͫͯ̑͒ ͫ̃̚o̐útͩ̍̉ ͒͂̍̿o̐rͥ͌deͥrͥ̑̐̈.̒̅̈́ͦ̓ ̔̅̈́̃T̋h̏̅͛eͭ ̍ͬ̓Ṅ̂̂e͆ͥ̃ͧ̏̀z͒̋̏̇̑peͬ͗̊̾̌̽ͦrͭ̒͒ͪd̀̋̅̔̿̔̄iͨ̆͐a̓̂̎̚ṅ hiͬ̓́ͪ̓v̂ͪ̎͋ͤ͑ė͒̐ͪ͛͐ͥ-͌̓̈́̒mͨĭn̾̅d̔ͭ ̄̃ͪ̆ͫ͂o̾f̋ͩ̍ ͮcͬ̏͊h̒͊̌̍̈́̓a̐͋̀o͆ͤ́ͭ̑ͮ̄s̀̃ͮ̓ͬ. ̆ͪͧͣͩZ̈́a̎̇l͌́gͪ̒ǒͦ̎. ̾͑̐̇ ͑̌ͥ͛ͩ̚H̆ͧ̓e̍͊̒ͣ w̄́̀ho͐͋̍̌̎ͪ ̊̇͗͛̓Wͪ̅ä̇̍̌̄̈́̏ìͥ͗͌ͣͤt̾ͮ̒̽͌s̍͊ ̎̅̿̌Bͤ́ͬe̊͂̾̀̆͆̇ḧ́͂͑̇͋̄̾i̎ͬͬͨ̒̽͑n̉d̾̏̈́͊̌̄̓ ͦ̅ͬ̃T̂ͧ̚hͧͨ͗̂͂͋e̎̓ W̃̽͋͐̀a̍̈́̆̓̐lͫlͧ.̾ ͒ͤ͌ͪͭZ͂̾͂̄͗ͦẢͪͣ͌͑̒̐LͦGͦͩ̓ͧOͭ̎̒͑!̇ͪ͐ͩͨ Zalgo
H҉̵̞̟̠̖̗̘Ȅ̐̑̒̚̕̚ IS C̒̓̔̿̿̿̕̚̚̕̚̕̚̕̚̕̚̕̚OMI҉̵̞̟̠̖̗̘NG > ͡҉҉ ̵̡̢̛̗̘̙̜̝̞̟̠͇̊̋̌̍̎̏̿̿̿̚ ҉ ҉҉̡̢̡̢̛̛̖̗̘̙̜̝̞̟̠̖̗̘̙̜̝̞̟̠̊̋̌̍̎̏̐̑̒̓̔̊̋̌̍̎̏̐̑ ͡҉҉
This package is directly inspired by @rnapier's talk at UIKonf 2020 and is basically the same implementation, just wrapped into a Swift package. Thanks Rob for the very entertaining talk!
1> import Zalgo
2> "He cometh".zalgo()
$R0: String = "H̴̬̦̱̥͚̭̗͋͘e̢͚͊͌ ̵͈͓̭͖̈́ͫ̎͊̿c̫õ̋m̡̰͎ͯͥ̃͘ĕ̃ͨ̊t̨͒́͏ḫ̶̠̪̉̄̈̇̚"