If you could create a Dark Souls boss

[L. Declis]

A Pursuer that actually pursues you.

No really. I'd take the concept of The Pursuer and give it some HEAVY buff when it comes to adaptability. My first idea is 1. He is about your size, maybe slightly beefier for intimidation reasons. I like the pursuer's design, but what that boss really needed was that "rival" look. A sort of Vergil to Dante connection.
2. is where it gets fun...
His appearances are COMPLETELY random, much like invasions. There will be times in which you should be prepared, cause when the signal that he's coming comes, he will swoop in and you will have to stand your ground then and there.
And 3. He gets a completely new moveset every encounter. It can range from being quick, to heavy hitting, to even him going more defensive/able to counter your moves. All that matters is that much like him, you must adapt to the situation FAST.
It's very un-Souls like to be that fast paced, but I believe Souls game's bosses should be a lot interesting instead of just hard for the sake of being hard.

Yeah, this sounds cool.

The Persuer wasn't really much of one. Imagine him showing up and semi random times all over the place, intent on ravaging your sweet little ass with a new moveset every time he does.

You see, I think this would be cool; think Nemesis from Resi Evil 3. He will occasionally just show up, or follow you from room to room. Keep moving or he'll turn up and kick your arse. No more camping and such.

Maybe he will ambush you outside bonfires, where you're hurt and injured and you need to get there but he is standing in your way. PANIC FIGHTING, DON'T PANIC!

 

[MasterOfHisOwnDomain]

I want a sort of sneaky, "wall shadow" boss.

[...]

Oddly similar to my own thoughts actually. I've always thought that a boss with the mobility of Ornstein, but able to dash from certain locations; a kind of shadow warrior ala Zed from League of Legends. The player would fight him in a giant hall with columns from which we could appear, or from shadow pools. Means you have to be on constant alert.

 

[Benni88]

Something inspired by shadow of the Colossus maybe? Perhaps the boss is actually the surface that you battle on, like the back of a giant monster, and you fight his minions on the surface until you have opportunities to attack the boss itself. You could mislead the player by showing them a new enemy who they might mistakenly believe to be the boss, until the floor underneath them starts moving.

 

[go-10]

a wall... yeah that's it. I'd make a boss that as you approach it it's just a wall however when you touch it it turns into a demonic wall with hundreds of mouths, arms, and eyes. The mouth spew toxic gas that can poison a certain area, the arms punch and grab you, and the eyes shoot lasers in a vertical or horizontal line. It also does a shrieking scream that can momentarily cause heavy on the player and if it manages to get you close enough through multiple grabs it can one hit kill you by grabbing and eating you.

it can't move so all you need is to keep your distance and use arrows/magic to kill it only watching out for its poison and eye lasers. However killing it with melee attacks will guarantee a pretty cool and powerful helmet and gives you access to a door behind it that leads to a small treasure room and a shortcut to a bonfire

Later on in the game you face 2 of them in a hallway so there's less room to maneuver but they loose the one hit kill move

 

[Blacklight28]

I'm all for a doppelganger. Exact same items, stats with only a slightly altered appearance. But along with that some advanced AI that lets it adapt to your attack patterns using the items you made available for it.

 

[WhiteFangofWhoa]

A boss using an idea from a previous post of mine that changes depending upon the current season IRL. It will possess 4 different sets of attacks, stats and weaknesses to different things. Winter can jam its clawed arm into the ground to generate ice spikes and roll around as a giant snowball. Summer can summon swarms of poison wasps and use a great flaming sword in its arm. Autumn summons storms of sharp leaves and its sword arm changes into a tentacle that drains your health and gives it to the boss. Spring causes torrential rains that block out the sun, making it more difficult to see and making the floor slippery, as well as having its arm change to a pair of vines to lash or grab and toss you with. His arm becomes a different weapon with each season. I will call him Vertumnil after the Roman God of seasons.

However, because this is Dark Souls, there will be another nasty twist- on New Game Plus, if you face Vertumnil in a different season than last time, he will split into two, one using the pattern from the previous playthrough and another using the current season's power. If it's still the same season he will simply have his twin use a randomly selected second power. On the third playthrough he will have three of him using three powers, and on all the New Game Plus after that he will combine all four powers.

 

[Nepukadnezzar]

I actually miss the classic "Earthworm"-Boss in Dark Souls ...
A Boss that burrows around and you can only hit it when it resurfaces.
That in and of itself is not particularly hard, but if you beat it enough, you get swallowed by it. Yes, it has to be gigantic.
What will be happening inside? I have no idea.
But I would like it if you have to fight your way out somehow, finally bursting out of the sides of this huge worm.