Hope I got it right.

AsheSquare Ashe : We must have a new era of peace!

LissandraSquare Lissandra : I support you, Ashe! (not)

SejuaniSquare Sejuani : Oh f**k you Ashe, you're stupid! This means war!

TryndamereSquare Tryndamere : DIE MONSTER, YOU DON'T BELONG IN THIS WORLD!

AniviaSquare Anivia : I must save Freljord from the poison.

VolibearSquare Volibear : Fight, my brothers! WE ARH SPEHSS MAHREENS BEARHS!

ZileanSquare Zilean : Shut up, Volibear.

TrundleSquare Trundle : I trolled the lion my dead ex-leader, the witch, and the wardrobe my clan. I am king, HUE.

NunuSquare Nunu : The Frostguards are evil!

OlafSquare Olaf : Kill me before I kill you! WHY CAN'T I DIE?!

BrandSquare Brand : I hate cold, Hax Sign "BURN EVERYTHING!"

GragasSquare Gragas : I'm drunk. More booze please.

UdyrSquare Udyr : Why am I here? ._.

Lee SinSquare Lee Sin : Just passing through. Come with me, Udyr.

QuinnSquare Quinn : I'm uh... just passing through here too... ignore me...

ValorSquare Valor : *caw* (Hey, Anivia darling, wanna be my girlfriend?)

Conclusion - Freljord is now Three Kingdoms. Guess which Freljord character goes with which Three Kingdoms character?

EDIT: AsheSquare Ashe, with her hardship during her childhood life, who wishes to unite Freljord into a peaceful country, is Liu Bei.

SejuaniSquare Sejuani, a woman of ambition and a "Hero of Chaos", is Cao Cao.

LissandraSquare Lissandra, having a facade that she supports Ashe, but secretly wants the whole Freljord for herself, is Sun Quan.

TryndamereSquare Tryndamere is pretty much Guan Yu, a feared warrior that will not stop until he finds the one who destroyed his childhood.

AniviaSquare Anivia, wishing Freljord to be someday pure, decides to support Ashe, is Zhuge Liang.

VolibearSquare Volibear, who sees Sejuani's ambition as the right path for his kind, is Zhang Liao.

OlafSquare Olaf, who just purely wanted to battle until he dies, is Pang De.

TrundleSquare Trundle would be the scheming Sima Yi. Although Sima Yi is not Wu (does not serve Sun Quan), it fits, because he's a scheming troll biding his time, and it won't be surprising that he'll backstab Lissandra, if he can.

GragasSquare Gragas would loosely be Pang Tong, who tends to get drunk not doing "anything" as well.

NunuSquare Nunu is a category of its own, there isn't anyone that could fit Willump and Nunu, except maybe Meng Huo and Zhu Rong.