I thought Saturn was the time keeper. I would say... Moon-Pluto might make them really feel like they need each other, but only time (Saturn) will tell.

I agree on there having to be some Saturn in the mix! Preferably contacts to Moon. I have the "we've known each other forever" feeling with people I have Moon/Pluto, Venus/Pluto or both in synastry and/or composite. But not have been meant to be with me in this life. 

I think Sun, Venus, or Moon contacts with Pluto or Saturn. Pluto comes on strong and is compelling and overwhelming like an addiction. So it's hard to kick, especially if you have a subconscious need for drama. Saturn is different - it is hard to break because of the time and investment you put in, you don't want your efforts to go to waste so you stay with it for the long haul.

Sun and moon contact.

I have moon square pluto with my boyfriend he's the moon and also venus trine moon moon trine moon sun trine sun square saturn and lots of saturn so it's kinda crazy but we been through stuff most ppl wouldn't handle and it's just too hard to leave for both of us it seems like

emotional devastation is pluto to venus, moon, mars or sun… pluto power and almost never mutual give and take, usually its the planet person left in emotional devastation.

Nodal Contacts. Ive found South node contacts to be very strong like pluto in the beginning but easier to break off after time (you get to the point of NEEDING to move on, like your wellbeing depends on it) while North node contacts are less magnetic initially but MUCH more difficult to let go of, you really are left concerned for the other persons well being almost more than your own.

also, BML and lillith are for me the most obsessive and crazy similar to Pluto but on crack LOl, those relationships never went anywhere, in retrospect. THANK GODDESS!

eros-psyhe I still cant let go of the memory of a  person I had this connection with in a romantic sense.

Chiron connections never start out as fun, they end up deep you give away secrets with glances, you become vulnerable to the other person in ways you have not before, and it feels like part of you is missing when the relationship ends-emotional castration and the mourning never fully goes away (I hope this makes sense).