I listened to the latest TTV Podcast last night, and I wanted to expand upon Kurahk/Kualus’s pitch.
There are two Ihuan royal families in this pitch. For simplicity’s sake, lets call them the Kualus family and the Izotor family. The Kualus family was the first of the two. An Ice-Matoran by the name of Roodaka felt that the royalty was too weak, so she tried to create her own. Kualus/Kurahk was the last member of his family and disguised himself as an average Ihuan. He wanted to have his revenge against Roodaka for destroying his family.
Decades later, Roodaka saw that she could twist Prince Izotor’s mind for her own personal gain. Kualus went out of hiding and spied on the Izotor family. He hoped for a time where Roodaka was most vulnerable so he could defeat her and restore the glory of the Kualus family.
One night, Kualus entered Prince Izotor’s room from the shadow. He woke him up and warned him about Roodaka. Kualus did this because he believed he could use the prince against Roodaka. He swiftly left as to not raise suspicion in the castle.
Prince Izotor kept Roodaka away from him at the best of his ability until he became Toa Kopaka. Meanwhile, Kualus joined the Brotherhood of Makuta so he could quench his anger against Roodaka and became the Rahkshi Kurahk.
On one momentous day, Roodaka killed the king of Ihu to attempt to give herself more power than she already had. Kopaka had enough and attempted to avenge his father by defeating Roodaka once and for all. This was the perfect time for Kurahk to step in. In a crazy turn of events, Kopaka and Kurahk worked together to defeat Roodaka. Their united strength allowed them to defeat Roodaka.
Ever since, Kurahk still has great anger in his heart ready to be unleashed on Kopaka. Tensions rose yet again between the Mangaians and the Ihuans the Mangaians found out about Kopaka fighting alongside a Rahkshi.
That’s about it! For those curious, I was in the middle of typing this when @Kaboomarak posted his Kurahk pitch. What a coincidence! 
I hope you all enjoyed my interpretation of Roodaka in G3.