Very impressive indeed, though I would like to also say that the relationship between Diana and Nami is also speculative. Still very impressive. Out of my friends who play League, I'm the one who cares the most for the lore, so this'll help me in discussing it with them and figuring out things for myself. That, and I also love relationship charts. XD
How long did this take you?

Fair enough with Garen and Kat, but for Varus, "He left [Ionia], seeking the blood of all Noxians involved with the invasion, a grisly task that eventually led him to the invasion's most infamous perpetrators in the League of Legends. "

He specifically came to the League of Legends just to hunt down the Noxus Champions that were involved with the Ionian invasion. Riven and Katarina were both there in Ionia in the invasion. Katarina got some of her first bits of action there (provided the old lore is still somewhat valid) and Riven had her command blown up by Singed. If he is going after the Champs from the rematch that would add Miss Fortune, Morgana, Singed, Vladimir, and Sion to the list with the possibility of the Reserves: Kog'Maw, LeBlanc, Rammus, and Shaco. If nothing else Katarina, Riven, and Warwick (here was there too as mentioned in JoJ 12) are on his list with Singed being another probable even though he is from Zaun (him and Warwick teamed up against Soraka during the fall of Ionia to Noxian forces).

A couple changes:
Brand is from Lokfar
Graves is from Bilgewater
Rengar lives in the jungle
Malzahar is from Shumari Desert
Blitz and Viktor should be related
Caitlyn and Vi are anything but friendly with each other
Rammus cant stand Twitch
Blitz cant stand anyone from Zaun
Pantheon and Leona should be romantic
There should be another connection: "Rivals" this is more fitting for many cases

Also these are just suggestions
If I got anything wrong let me know.

So far, I've put about 6-7 hours worth of time into this.

That's really neat and helpful. ^^ Thanks for making that.

Brand is not from Lokfar; the body he is possessing is. Brand himself was imprisoning somewhere in the north (that wasn't Lokfar as he was found somewhere artic waters), but even that doesn't mean he came from there; just that he was found there.
Caitlyn and Vi are friendly together. They are a very effective crime fighting duo. Vi teases Caitlyn, and Vi doesn't always play by Caitlyn's rules so Caitlyn has a hard time getting Vi to behave properly, but that doesn't mean they aren't friendly to each other. Vi is just a bit unruly. Pantheon and Leona were friends but they drifted apart after Leona ascended; nothing romantic there at all (besides Diana and Leona make a better couple /)^3^(\ ).
http://na.leagueoflegends.com/board/...84485#27884485

I didn't know Tryndamere and Ashe were romantic =P.

I'd be willing to bet that Teemo and Tristana have hooked up lol.

Technically speaking, the connection between Diana and Nami is speculation only. We can assume with a pretty high degree of accuracy that the moonstone is connected to the Lunari, but we have no real way to back that up. I'd change the line to speculation.

Other than that, this is great. I love these informatics

Great work, but typo: "Currentl Imprisoned"

This is really cool and I posted the link to this thread on Reddit. I hope you don't mind.
If you do, I will remove it immediately.