Not exclusively no. I played mostly Co-op, but I played plenty of characters on my own to try to “catch up” with my friends when my main character who I was playing with them died. You have to remember that Diablo 2 had rejuv potions, which were instant cures. I did die to Duriel as a hardcore Amazon a couple of times, and discovered never to go in there alone. So there were a few solutions to that in Diablo 2 with the Amazon:
- Go in with a Valkyrie. But this wasn’t liable on normal difficulty, since you couldn’t get to level 30 when a Valkyrie becomes available as a skill.
- Go in with a Mercenary (we used to call them slaves).
If you can keep your distance, Duriel concentrates mostly on the second person in there. If it’s a Valkyrie, you can keep summoning a new one while gulping down mana potions. One lasts a while, even to Duriel. If you don’t have a Valkyrie yet, you can keep your mercenary alive by feeding him potions while you kill Duriel. If you can give your slave a weapon that can slow down Duriel or stun him, it helps a lot.
If you’re in with a Necro that can summon, it’s no problem at all, you can keep Duriel occupied forever. If you’re in with a sorceress, you have to rely on the merc again, but he doesn’t have to last as long as he does with the Amazon, since the sorceress deals so much damage with Static field, and other spells, she can get him down to nothing in no time flat. If you’re in with a Druid, again a merc or wolf summons will do the job of distracting him. Barbarian can handle him no problem by himself, as can the Paladin. Assassin might need the help of the merc, depending on what type of Assassin you made.
Once he is distracted and hitting someone else, you can create a portal in his chamber and get out if you need to go get more potions or something like that. By that point you can even create rejuv potions if you run out, since you have the Horadric cube.
As for slow loading: I don’t really understand what you mean. If it loads slowly, you won’t have to deal with him until it finishes loading, right? Or are you talking about playing on Battle.net? I’ve never played on Battle.net for that reason. I just can’t deal with lag and other such issues. It’s too much when you already have to worry about not getting your hardcore character killed.
Nevertheless, you’re right. Duriel in Act 2 Normal difficulty comes closest to this sidequest boss in Titan Quest in terms of how fast he can finish off a player. I suppose Diablo himself could do it too, if you didn’t invest in enough Vitality, but since I only play hardcore, I’ve never had a character reach Diablo without having lots and lots of Vitality. Certainly enough to survive a couple of attacks by Diablo that he’d make before you had a chance to run away and regroup. Plus again, the Rejuv potions make a difference.
It will be interesting now that Diablo 3 won’t have rejuv potions. Without instant healing, they’ll have to balance their tougher fights a little differently I think.