I know what you're thinking. "Who is this cheesy looking Darth Vader knockoff from the 70's?"
Right?
He was the main villain in New Rebellion and was mentioned in the novel to have attended Luke's academy in the early days of its creation. Though possibly one of the first class of students its never verified which is why I mentioning him now.
At Luke's academy he went by the name "Dolph" and left early due to a war on his home planet that resulted in the death of several of his race. Seeking revenge upon the perpetrators, Dolph turned to the Dark Side and became Kueller. Eliminating the enemies of his homeworld, Kueller set out to conquor the entire galaxy on his own.
He attracted fallen students from Luke's academy such as Brakiss before ultimately perishing during the end of the events of New Rebellion.
I remember how the book ended. They took off his mask to reveal the peaceful boyish face of Dolph underneath, which was a striking difference to when Luke unmasked the deformed and damaged face of his father after the events of Battle of Endor.
I would've like to have known more about Dolph's early training at the academy and personally enjoyed the stand alone novel by Kristine Katheryn Rusch. Though Kueller does resemble a cheesy version of Vader, I like the design of his armor too. He looks like he came from the old Marvel comic's Rogue's Gallery.