Edit: I've read through more of this thread and find that this is not your child and that
you are among the siblings. *sigh*
Here is the advise I'd give to a parent in this situation:
I'd talk to the siblingss separately and soon - not in the middle of trouble, but at a neutral time. They can give you insight into what's triggering the upset in the toddler and you can work
with them to decide on strategies for including the toddler in ways acceptable to them as well as a signal that they can give to you to interfere to remove the toddler from the situation before things spiral out of control. Then you can talk to the toddler
before playing with the siblings again. Talk him through those strategies you decided upon with the older kids for managing play time together, and let him know the consequences ahead of time for bad behavior (removal from play is best - I like to stick their backs on the wall :chuckle: I don't know why this works, but it does, and I wind up swinging the paddle a whole lot less for the same, or better result).
Shadowmaid, you should talk to your brother before you play with him - before he thinks he's in trouble. Tell him that you would love to play with him,
but you will stop playing with him the moment that he begins to scream. Tell him that as soon as he starts to get mad to say "Shadowmaid

chuckle

, I'm getting mad." Ask him to practice it for you and agree, out loud, to say that if he starts getting frustrated. Then, if you notice him getting mad, ask him if he's getting mad to prompt him to say what he's practiced. Then you can see if he will talk to you about what is getting his goat. You can maybe have a very good conversation about sharing and taking turns since he isn't all mad yet - just beginning to get mad and you've short-circuited the regular routine that ends in a screaming fit. Remember, toddlers scream because their conversation skills are too limited to tell you without help what's bugging them. So help him tell you
before the screaming starts. You will be able to tell when he's getting frustrated before he can.