G.I. will literally surround this character! (5)
I believe the answer is:
aitch
'g i will literally surround this character' is the definition.
'aitch' can be an answer for 'character' (the spelled out name of the letter H). I am not sure about the remainder of the definition.
'i will literally surround this character' is the wordplay.
'will literally' becomes 'atc' (I can't explain this - if you can you should believe this answer much more).
'surround' indicates putting letters inside.
'this character' becomes 'h'.
'i' inserted within 'atc' is 'aitc'.
'aitc'+'h'='AITCH'
Can you help me to learn more?
(Other definitions for aitch that I've seen before include "that I will immediately succeed" , "character leading heroes" , "8th letter of the alphabet" , "It's dropped by Cockneys" , "first bit of hymn?" .)