GAME OF WANDS PREQUELS: THE TOURNAMENT

The finale of Winter Roses shows us both the Triwiz Tournament, held at Hogwarts, and the wedding of Rhaegar Targaryen to Elia Martell, the latter done as a musical episode. Characters from The Wind on Fire and other 1990s novels appear in the crossover.

The tournament itself takes place this time on the grounds of Hogwarts, the year after the one. Jaime Lannister returns as a Durmstrang student, much to Cersei's and Tyrion's elation. Renly returns from Storm's End to cheer on in the tournament. Tyrion is now a bullied Ravenclaw student, who shields himself from a hostile world with a cuirass of learning. Elia, now a university freshwoman, is tasked with overseeing the Tournament. And Oberyn reappears making an entrance as usual.
Rhaegar, now prefect of Ravenclaw, helps Tyrion to socialize. Ned and Stannis comment on the tournament. And Lyanna gets a slightly eccentric Beauxbatons kouhai who appears to be royalty...
The subplot features the Cold War raging on and Westeros in the middle of international intrigue. Due to her friendship with Sisi, Lyanna finds herself in the eye of the hurricane...

New characters:
Marius Semeon Ortiz: a young and dashing general at the service of a distant land, the beautiful country called the Mastery. Makes friends with Rhaegar, and fiancé to Sisi, but falls for Cersei by mistake. He is actually the ward and heir to the national dictator, the learned and wealthy Master Albard (who wanted to marry Sisi himself), sent to hijack the tournament. His neck gets broken... Killed by henchmen sent by Tywin Lannister, on the eve of her wedding.
Sirharasi "Sisi", Johdila of Gang, Wonder of a Million Eyes, Pearl of Perfection: Amber-eyed and dark Beauxbatons student, princess ("johdila" is her title) incognito. Beautiful and sweet, but spoiled and childish.
Innocently insensitive. Lacks social skills due to her sheltered unbringing as an only royal child, but makes up for it with enough luck and pluck. This Dornish-looking (though not Dornish) maiden calls Lyanna "Upperclass" and looks up to her...
Her parents, the Johanna (male, Lord of a Million Souls) and Johdi (female, Mother of the Nations) of Gang, are revealed to be refugees in a village on the borders of the Mastery, devoid of all their trappings, dethroned by the leader of their ranks.
It is revealed that the Domination of Gang has rhoynar origins like Dorne.
Sisi falls for Jaime Lannister, in spite of the competition that has them face each other. She isn't fond of attending to her duty. She also has a pretorian guard the size of a regiment, and its commanding officer loves her. In the end, after the battle was lost, it is revealed that the land of Gang has been occupied by the Mastery, making her a dethroned victim of war.
(In the end, after the War of the Usurper saga, it is revealed that she defeated Zohon and reconquered the empire of Gang, which now encompasses the former Mastery. Sisi has become the Sirhardi, Mother of the Nation, and is in a relationship with Oberyn Martell himself, having had five children by him at the palace of the realm.)
Lunki: Sisi's maidservant and confidante, a stout woman in her forties, and part of the Beauxbatons personnel.
Zohon: the tall and dashing commander of the Johjian Guards, a heart-throbbing military officer in unrequited love with his liege lady. Poses as a Durmstrang disciplinarian. Involved in the Cold War as dictator of the realm. Jaime mistrusts him a little, having not seen this good-looking fellow at Durmstrang... Rivals with both Rhaegar and Robert. In the end, Zohon returns to the Mastery. He dethroned Sisi's parents and took over their court until she consented to marry him. Which she will never do.
CHAMPIONS
For Hogwarts: Rhaegar Targaryen (Ravenclaw)
For Durmstrang: Jaime Lannister
For Beauxbatons: Sirharasi "Sisi"
Spare for Hogwarts: Lyanna Stark