Legate LANUIS replaces Rikke as Tullius's second in command
What would happen?

Terrible, terrible things.


And... I admit to accidentally switching their names before. So Lanius has already served Tullius according to me.

He would probably win the war single handedly, take Ulfric alive, and do the worst possible torture to him infornt of the emperor.

If Lanius was Tullius legate the Stormcloak rebellion would have died with Ulfric the day after it started.