Complex sentence: Engelstad was known as a self-made man, and one of the very few independent casino owners in Las Vegas; he also was a great philanthropist, even aside from his work with the arena, but will probably not be remembered in a positive light.
Split into simpler sentences: Engelstad was known as a self-made man, and one of the very few independent casino owners in Las Vegas. He also was a great philanthropist, even aside from his work with the arena, but will probably not be remembered in a positive light.