A Delay in the Stream

Recently, I've been playing a lot of this game I bought on Steam called Crypt of the NecroDancer. While playing it a couple of days ago, I came up with a funny idea for a boss, which caused me to wonder if there was any way to create your own monster characters on there. I would like to create this boss idea for some laughs while playing the game on my Twitch channel. Does anyone know if there is a way to do it? If so, could someone explain it to me? I have the name for the boss monster I'd make if it were possible to create it, but that's a secret. It's best not to reveal that kind of thing until the idea is complete if it's possible.

On my Twitch stream that I've been running for a couple of months now, I've mostly just been streaming Jackbox Games. I host them all, except for "You Don't Know Jack". The reason behind that is that the stream isn't in real-time. There's always a 15 to 20-second delay between my PC and the people watching. Since you only have about 20 seconds to answer the questions on that game, the delay doesn't help. There's no way for people watching to play that game unless they can answer within 5 seconds or mindlessly guess. That's another question I have. I use OBS to stream on my channel. Is there any possible way to reduce this delay, or is that delay inevitable no matter what you do?

Another game I stream on Twitch that people can join in with is Choice Chamber. The pain with that game is that it's effortless to die, and I'm the one playing it mostly. People interact with choosing what weapon I'll be using, the kind of jump I'll be using, etc. If I suck at controlling the character, then it's not all that much fun to watch since I'll constantly be dying before I even get that far in the game. Now the question is, are there any other games like the Jackbox ones where loads of people can interact without owning the games themselves, or is it just those?