Source: Starfinder Core Rulebook p.112
The arcane assailant fighting style supplements its combat effectiveness with magic powers, drawing on traditions of warrior-wizards dating back to well before the Gap. This allows you to use magic runes to augment your weapons and call on legendary powers, giving you access to arcane options even when you don't have a magic weapon in your possession.
You can imbue a weapon with a magic sigil, the rune of the eldritch knight, allowing the weapon to act as a magic weapon for the purposes of bypassing DR and affecting incorporeal creatures. This takes 10 minutes, and you can imbue only a single weapon at a time. If you imbue a new weapon with the rune of the eldritch knight, any previously imbued weapon loses this benefit. When calculating the Hit Points and hardness of a weapon imbued with the rune of the eldritch knight, treat its item level as 5 higher.
When you imbue a weapon with the rune of the eldritch knight, in addition to its normal benefits, the rune grants the weapon one of the following weapon fusions of your choice: ethereal, flaming, frost, merciful, or shock. The weapon can't gain a fusion it already has, and this bonus fusion doesn't count toward the maximum total level of fusions the weapon can have at once. The bonus fusion ends when the weapon ceases to be imbued with the rune of the eldritch knight.
You can call on the link between you and the legendary heroes who wielded powerful magic weapons eons ago to overcome adversity. As a move action when wielding a magic weapon or a weapon imbued with the rune of the eldritch knight, you can spend 1 Resolve Point to end one of the following conditions affecting you: bleeding, burning, confused, exhausted, fatigued, flat-footed, off-target, shaken, or sickened. Alternatively, you can spend 1 Resolve Point to change the cowering condition to the frightened condition or change the frightened condition to the shaken condition. In this case, the new condition lasts for the same duration the original condition would have and can't be further affected by this ability.
You can imbue two weapons with the rune of the eldritch knight. If you attempt to imbue a third weapon, the weapon infused first loses its rune and all benefits. In addition to the normal benefits, the runes grant the weapons one or more of the following weapon fusions of your choice: bane, corrosive, ethereal, flaming, frost, holy, merciful, shock, thundering, or unholy. You can grant no more than 10 total levels' worth of fusions between the two weapons, and the bane fusion counts as a 10th-level fusion for this purpose.
As a standard action, you can spend 1 Resolve Point to use a weapon imbued with the rune of the eldritch knight to make an attack that strikes true. This attack ignores all cover and concealment, including total concealment (though you must at least be aware of a creature's presence to target it with this attack). If the attack is a ranged attack, the target must be within the first range increment. The attack only affects your selected target, even if it normally affects an area or multiple targets. You still must make a normal attack roll, and if your attack misses, it has no effect.