Kopa's last fight

If somebody don't know, Kopa are the son of Simba and Nala ( in ' The Lion King:Six New Adventures) and Kiara's 'big brother', but Kiara don't appeare in the 'Six New Adventures' and Kopa is only a book character.
Someones say Kopa is maybe that cub who appeared at the end of The Lion King, but he's not in the next movie, The Lion King: Simba's pride. Disney has proved cub is not Kopa, she is Kiara.
Still I wanted draw Kopa and his story would be boring if fans have not invent their our stories for Kopa. So what happened to him if he would be movie character?
My favourite theory is that Kopa was killed as when he was cub.
Was Simba's fault that Scar get killed by hyenas, and then Zira become angry because she loved Scar. Zira wanted avenge to Simba, and when Kopa was alone farther away from Pride rock, Zira attackted and killed young Kopa. Later Simba and Nala found death Kopa. That's why Simba is very protective of his new cub, Kiara.

Poor Kopa ;^;