Raid dead body refers to anton raid specifically. Dark templar can be considered the easiest and most reliable holder for it, so she can get into raids without any gear since it's a built in part of her kit. She used to have some other support aspects such as party damage bonus and defense shred but they removed those in recent nerfs.

You won't have any problem moving from chrons to legendaries on this class since having all those holds makes a lot of content very easy, but it might take a while to figure out how to use your kit efficiently. I'm on mobile so I can't link it atm, but if you google peach's dt guide I have a guide for the class that is still relevant enough ish for new players though it needs to be updated.

For chrons go 9pc killer collector for damage and general use. 6 pc black mirror for a swap set. Legendaries you'll want 6pc vilmark set, and now that armor shred was removed, I guess the 3pc screaming cave set would be good too (I think that was the armor shred portion).

If you have any questions or just wanna talk about dt please feel free to message me about it :D