As a mid renekton main from bronze i want to show how to totally dominate mid, so heres some tips and tricks;

His q gives him sustain he needs to survive against ranged and mages, and makes his farm and ability to push extremaly easy.
Renektons w is essential in this kit, and how well it combos(?) with press the attack from runes, essencially with this ability you can oneshot lvl 3.
The Renektons w is really good too, you mostly will use it as gap closer.
R is really strong as it generates a lot of fury and gives massive chunk of hp.

Renekton playstyle is similar to katarinas and its very nessesary as you do not scale very well towards lategame, so you want to end game before it comes to lategame (past 30 min)
You have to make pressure on every lane, and roam as much as you can.
You can roam very easly beacouse you can use your q to push and not lose farm.
There comes Prowler's claw with it's active making renekton unescapable roaming mashine.

Renekton has very little counters, but mages are big threat for him, and ADC's like lucian mid are quite rough to play against.
Basically hes weaknes are typical toplaners counters.

I hope my mid guide made sense.
Does it make sense?
Pls respond.