How best to deal with temper tantrums in toddlers?

In all reality, you are doing exactly what you should be doing. Children crave familiarity, and to be yanked away from the mother for a second time no less, the child is in a mental uproar trying to assimilate what is going on in his world. The best thing to do is continue showing all the love and support that you are currently doing and just nurture him as much as you can. Do things with him that will take his mind off the other stuff that is going on currently. He is almost in the terrible two's, which really stinks because it is as bad as advertised. Is the child cutting teeth? He is right around the time when new teeth should be coming in and it is quite painful for a child. This could be causing the child some discomfort and could be a root cause of the tantrums. Other than that, just keep doing what you are doing and eventually, he will stop the tantrums. Kudos to you for stepping up and taking care of the child in a difficult situation! It is going to be a rough road, but at least the child is with his family, and it is obvious that his family cares deeply about him. God bless you!

You are doing the right thing by trying to ignore them, as long as he's not hurting himself continue the way you have been.

I have found distraction a good way to stop a tantrum, what i do is i'll walk over to an object, pick it up and hide it from the childs view, then i will say things like "ohhhhh, look at that! wow, thats lovely" things like that. The child become curious as to what you are looking at and forgets all about the tantrum they are throwing.

One thing that would probably help is to have a quiet corner. A little section of a room filled with cushions, cuddly toys, pretty pictures, and books. When he starts a tantrum you can say, "I can see that you're very upset. I think some time in the quiet corner will help you feel better." In this case I would act as though the tantrum is something that is HAPPENING to him rather than something he is DOING. This will help him see it as something he can manage.

In the quiet corner, if his tantrum subsides and he looks around him, you can softly ask, "Can I come in?" and then point out some of the books and ask if he'd like a story. But if he starts screaming again, just say, "Do you need some more time to be upset? I can come back" and go do something else.

Just hearing this child's history, I would definitely allow him to express his rage in a safe and controlled environment.