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A lot of Ultrasabers hilt designs are completely original designs. However, some of them are taken from movie hilts or game characters. I'll do my best to remember as many as I can:
Graflex - Anakin Episode III/Luke Episodes IV and V
Chosen One - Darth Vader
Guardian - Obi Wan Episodes I and II
Consular - Qui Gon Jinn
Menace - Half of Darth Maul's staff
Archon - Similar to Luke's Episode VI/Obi Wan's Episode III and IV lightsabres
Raven - Starkiller's 'Sith Stalker' lightsabre, from the Dark Side path in the Force Unleashed video game
Bellicose - Starkiller/Galen Malak's lightsabre from Force Unleashed II
Malice - Darth Malgus' lightsabre from the Old Republic game
Shock/Shock LE - Similar to hilts used by background Jedi like Aayla Secura in the prequel films. Within the expanded universe the explanation is that the similarity is down to them
Monarch and Dark Monach - Some people view these as being inspired by Sidious/Palpatine's hilts from Episode III because of the flowing lines, but it seems to me to be a loose inspiration at best
Flamberge - Inspired by the crossguard lightsabre carried by a character in the Episode VII trailer
And not forgetting the Omen, which isn't a Star Wars hilt - it's based off the Sword of Omens from the Thundercats cartoon