Reporter, one aboard the tube first, is a keyboard warrior (10)

'a keyboard warrior' is the definition.
The definition suggests a singular noun which matches the answer.

'reporter one aboard the tube first' is the wordplay.
I cannot really understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
'reporter' could be 'tv' (TV reporter is an example) and 'tv' is present in the remaining letters.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'first' could be 'i' (I in Roman numerals eg Elizabeth I) and 'i' is located in the answer.
The remaining letters 'hacks' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'is' acts as a link.

Can you help me to learn more?