Well he didn’t want her dead. Finn confirms this, with the info from D-O that Ochi was supposed to bring Rey to Exegol. I guess you could say that he wanted to raise her as his predecessor but when he lost her he switched to Ben.
At some point though you have to ask if he just supremely lucked out that Rey came back into the picture by herself?
Palpatine is evil and crazy. He wants people to submit to him or he wants them dead. If you are a pain he wants you dead. If he might be able to use you, then sure, he will take what he can get or he will kill you anyway. He spent two of the OT movies wanting Luke and then when Luke stood and declared himself a Jedi, Palpatine tried to kill him. So it makes perfect sense for the character to be inconsistent on wanting to kill or convert someone.