Menacing Weapon Fusion
(from Starfinder Armory)
A weapon with the menacing fusion aggressively pushes against your foe’s guard, making way for other attackers. When you hit an enemy with a melee attack using a menacing weapon, that enemy is considered flanked for all other melee attackers until the start of your next turn. This weapon fusion does not provide any benefit to your own attacks. Only melee weapons can benefit from the menacing fusion.