Maybe there was an experiment going on at the University of Piltover for a new security weapon that would be used to protect laboratories from intruders, but something went wrong with its AI and it went rogue. It can switch from different weapons and modes, for its basic it shoots laser beams, its q could be a more charged beam with a longer range, its w could be something like a protection system that gives it a shield for a few seconds, its could be a stun laser and for its ult it transforms into a stationary turret and charges up a powerful beam called Annihilation Cannon and as it's charging it says something like "Searching target. Target found. Target appears to be hostile. Activating elimination sequence. Charging cannon. Cannon is at 100% charge. Firing." If it kills an enemy champion with its destructive beam of death it says "Identifying target. Target has been eliminated. Switching to basic combat mode." The laser would be a single blast with unlimited range, but the farther it goes, the more energy it loses, dealing less damage to enemies farther away. However, it will pass through any number of enemies.