A Nautilus Buff Idea
When it comes to Nautilus, I honestly look at him and wonder where he went wrong, because to me Sejuani seems like a better Nautilus at the moment. Both have a gapclosing Q, except while Nautilus's won't drag him if it misses or only drags him to a wall, Sejuani's is guaranteed movement and gets her over walls. Both have a W that increased area of effect damage, but Nautilus is entirely reliant on his shield being intact. Then both have a slowing and damaging E, except Sejuani's is guaranteed to hit and technically has a longer range, so long as you tagged their team with frost. And while Nautilus's ultimate can pick out a member of their team and be very disruptive, Sejuani trumps it with the potential to absolutely demolish the competition and the teamfight by stunning the entire squad. She simply seems like a better Nautilus to me, so I started thinking what exactly would make Nautilus his own thing again?
First of all, what do we want Nautilus to be? I dunno about you guys, but to me and apparently quite a few other people, we want the Nautilus from the cinematic. An unstoppable force of vengeance that's just coming for you. So how do we create that? I don't recommend touching his Q or E, unless it's to nerf the damage for balance. Instead, I'd like to focus on his passive and his W. As it is, Nautilus's teamfight requires him to tag as many enemies as possible to disrupt the team, but in a meta with so many dash heavy champions or champions that can escape easily (Graves, Sivir (plus spellshield so you cant even ult or anchor her), Lucian, Rumble Shield, Lissandra, Azir, Kha'Zix, Rengar, Janna, Jarvan, etc.) it's almost completely impossible to perform his job.
What I suggest, is to allow the diver to enjoy CC immunity, similar to olaf, while his shield is active. He would also enjoy 20% increased movement speed to let him stick to certain targets and actually do the job he's meant to do. It will also help him in a thematic standpoint knowing that this unstoppable force of vengeance is going to chase you down. And no matter how many caitlyn traps, blitz hooks, silences, and flame chompers he walks through, he's still coming. (Even if it doesn't last forever!) In a teamfight, this will force your team to coordinate. Either avoid the Nautilus, or take out his shield and remove the threat.
The other option for his W buff that I have thought of is the addition of a Sion-Style detonation. This would slow targets by 25% and would damage them for 5% of their maximum health. This gives Nautilus something else to offer in a teamfight, but the reason I don't put this the furthest forward is because it's a Sion-Style detonation. "If a champion has an axe, no other champion can swing an axe that way." Right Riot?
I would love for others to give me some thoughts, because I absolutely love Nautilus and Sejuani as champions, and I don't want Sejuani to just be a bigger and better version of Nautilus.