Ah you are looking for a wider champ pool, not similar champs.
In that case, Cho'gath mid plays as the yang to ahri and lux's yin. He is not a poke or kite champ but rather an in-your-face bursty champ. He is every strong against champs like zed or talon, the ones ahri and lux struggle with a lot.
Ezreal is a slippery, pokey champion in bot lane. The opposite of him would be someone like graves, more bursty, with very little poke. A great pick against something like vayne because he dominates the early game and can set her back far. Alternatively there is jinx if you want more auto based dmg and still want a global ult.
If jax is top, he is a melee, brawling, auto-attack based chamion. Renetkon or pantheon are good if you need someone with a stronger early game than jax. Lissandra or kennen is a good pick if you need an ap top. Finally, sion or trundle are good if you are needing more of a tank. Top lane has a ton of variety so this is a difficult one for me to help without knowing who you are geting counterpicked by.