R6-H5/Legends

R6-H5, nicknamed Arsix, was the astromech droid of Jedi Master Kit Fisto.

History
Sometime during the Clone Wars Arsix and Kit Fisto followed a Republic tracking beacon to Vassek where they believed Nute Gunray was hiding. Master Fisto landed his Delta-7B light interceptor in the fog and told Arsix to stay put before he went to meet Nahdar Vebb and his Clone Troopers standing by a Nu-class attack shuttle. When the Jedi and the clones entered Grievous' castle, two clones, Bel and Niner, stayed behind with R6.



When the clones tracked Grievous' starfighter incoming, they reported to Commander Fil. Shortly afterwards Grievous' IG-100 Magnaguards destroyed the shuttle with both clones inside it, using a rocket launcher. When Magnaguards surrounded the starfighter, Arsix received orders from Kit Fisto to fly away, which he performed, shaking off a tenacious Magnaguard, who clinged to the fighter's hull.

Later Kit Fisto ordered Arsix to meet him at the south landing platform. But once he got there, he was outnumbered by Grievous and Magnaguards. At that point Arsix arrived in the starfighter, allowing Kit to leap on it and escape the battle.

Behind the scenes
If R6-H5 is indeed an R6-series astromech droid, and not just an earlier model with an "R6" designation, his inclusion poses a continuity problem, as R6 units had not been created until after the Galactic Civil War.

It might also be that R6-H5 is a prototype R6 unit, being tested with the Jedi Order.

Coincidentally enough, R6-H5 shares the "H5" with Kit Fisto's other droid, R4-H5. This is also the case with Plo Koon's droids R7-F5 (who helped pilot his Delta-7B) and R4-F5 (who helped pilot his later Delta-7.)