How do you counter Nautilus?

Leona provides her with enough crowd control to be able to unleash some of her higher damage moves, namely her E and her Ultimate.

Try to avoid Ezreal's Essence Flux ability, which can often be predicted and dodged. Arcane Shift is Ezreal's only escape ability. If he uses it to enter a fight, he can't use it to exit. Try to avoid bunching up with other team members in order to reduce the impact of Ezreal's ultimate.

Lucian's Relentless Pursuit makes him fairly mobile - stuns are an effective counter to this. Beware of standing behind minion waves as Lucian's Piercing Light may give him free damage. As Lucian is dependent on AD, building armour may prove effective.

Try not to stand near minions on low health to avoid taking damage from Explosive Shot's passive. Try to bait and burn Tristana's Rapid Fire as it has a long cooldown. Tristana's Rocket Jump can be interrupted with knock-ups and displacements.

Avoid standing in Varus' Hail of Arrows where possible. Try to avoid bunching up with other team members in order to reduce the impact of Varus' ultimate. As Varus is dependent on AD, building armour may prove effective.

The strongest counter would be Kog'Maw, a moderately diffcult to play champion who currently has a Win Rate of 52.65% (Good) and Play Rate of 1.7% (High). League of Legends most often picked champions vs Jinx, this is often heavily influenced by champion popularity.

Try to avoid her harass. Try to avoid Karma's Inner Flame, and leave its radius if Mantra has applied to avoid bonus damage. Avoid being tethered by Karma's Focused Resolve for long periods as it will eventually root you. As Karma is dependent on AP, building magic resistance may prove effective.

The strongest counter would be Maokai, a easy to play champion who currently has a Win Rate of 53.55% (Good) and Play Rate of 2.27% (High).