Which champions does Hwei work best with?
With engagers who immobilize or group enemies: Jarvan IV, Amumu, Malphite. Their crowd control makes QW, QE and R much easier to land and far more dangerous.
Why does Hwei need a frontline?
Because he has no dash or blink. His zones need a few seconds to take effect, and with nobody in front of him, enemies reach him before QE or R have done their job.
Can Hwei carry on his own?
He can take an advantage through poke and EW → QW picks, but his real impact comes from grouped fights around objectives. Without a team playing around his zones, he remains a fragile mage.
Which jungler should you pick with Hwei mid?
A jungler who engages and immobilizes, such as Jarvan IV or Amumu. He makes your combos reliable, protects your lane against enemy roams and turns every objective into a zone where your spells no longer miss.