A sharp tip, light metal durable frame and as long as your arm.
The basics to a sword made for a man. Or for a man to make his own. The tip must be narrow to split chainmail. The tip must be strong, so that it can also penetrate plate if you hit it straight or a dent. So the frame is good if you single side the blade or double side with a ridge. The ridge can cause it to be heavy. The single blade with a flat back could flex and bend when you don't want it to.
Making a sword is finesse and difficult. You must do it without bending it when cold, so it must be straight when it glows.
The balancing to the handle allows the sword to work with the wrist, like holding a staff in the middle. So it must be full tang(means the blades metal goes through the hand). This also means a weight at the bottom to cap the handle, this keeps the blade from slipping. Wet from blood or sweat, it must stay long after the organic handle wears away or tears off.
This weight at the end can be spiked, but know that this is yet another thing that the user must be wary of. So skill and training determines if this gets a spike.
The blade has many uses, the forward blade near the tip is a weak point and must slide other blades effortlessly towards the hilt where you can push. Or slip away to allow a return attack. This spot must be difficult to dent, for that will create a hook to end the user in combat. The hilt half of the blade can be jagged to make it hard for another blade to slide towards the users tip where the blade can be pushed easily. A spot where you could add a saw to cut wood perhaps. As long as it can catch the edge of a blade, even twist it.
A round edge is for penetrating soft armor. A spike is for penetrating metal armor, and it has to be tough for plate. The length of the weapon is like a spear with the arm extended. Yet it will not break like a spear.
A shield is optional, this item can be used against the user or be a life saver. A shield can always be dropped.