Genji originally had only a sword, and could execute enemy heroes with a single attack, according to lead Overwatch hero designer Geoff Goodman.
"His main kit initially involved invisibility, wall perching, and having an 'execute' animation where if he got behind you he could stun you and start this long animation which would just instantly kill you if he finished it," Goodman wrote.
"The idea was he could easily pick off people who were not with their team, but otherwise it would be very difficult to use execute [sic]."
Goodman said the sword-only combat was the main problem with this design, but that the kit caused "all kinds of problems."
"Once we moved away from invisibility and instead chased the agile ninja fantasy, and made the sword his ultimate, everything started clicking into place."
Evidence of Genji's original kit persists in Overwatch. The hero is still referred to as SwordNinja in the development team's internal files, a vestige of his original incarnation. NPC enemies from the Archives event missions known as Assassins sport both wall-perching capabilities and an execute ability reminiscent of Goodman's description.