1. Sure thing, I want to see the terrors on their faces as they beg for their lives.
2. Make sure they go through the process of dying like I did, but have a twisted addition. Such as, if they were struck by poison, paralyzation, or anything categorized as something that can be cured. It would be better if you limit their movements for explicit results. Make them beg for it as they crawl for their lives towards you holding the antidote in your hands. We would play with it and drag it further as they are slowly dying.
End it with me saying "Now you know what I have gone through because of you and your little pesty friends. I was begging for you to save me, but you didn't. And guess who's back in a flesh, yours truly. If only you haven't stabbed my back, this wouldn't happen. Don't make the same mistake in the next life, it's bad" right at their faces as I throw or destroy the antidote in front of them.
There's another method to also prolong their suffering though, make them into a potato. Or in conclusion, cut their arms and legs off, make them suffer that for their entire lives. Death is nothing but a short escape to their wrong-doings, to torture them is to make their lives a living hell. Down to the point where they think that death is better than being tortured endlessly.
Ehe
3. Live a new life
4. If they really feel what I have been through, I suppose giving them a second chance would be sufficient. But if they decide to back stab me again, they better prepare torture worse than those I have mentioned on number 2.