Red John = Reede Smith....

The name  "Reede" translates to " Red one " in Old English...So his name is really " Red Smith "....

Also...The RJ alias " Roy Taliaferro " translates to "King Smith "....

Further ..... The name " Smith " itself is from the Old English word "smitan", which means " to strike "....

So Reede Smith = "The Red One Who Strikes" with the alias " The King who strikes "

Read
the poem "Tyger Tyger " by William Blake...It describes a mythical
godlike "Smith " who creates a fearsome, deadly creature in a furnace
that exists either in heaven or hell....He uses a hammer and anvil to
imbue this "dread" creature with terror and death...

Blake isn't
talking about a real tiger of course... which is why he misspells it "
Tyger "...The Tyger symbolizes the evil that exists in this world ...And
Blake asks how the same smith that created the Tyger could create a
person like Jesus of Nazareth (the lamb )

Red John also thinks of himself as a godlike ( Smith-Reede Smith ) who can create an evil entity of great power....and he has created the  Tyger-Tyger Organization