Swinging them all around feels great, but doesn't work well. Despite what the massive size implies, they are not brute strenght weapons... mostly.

They swing a wide arc, but, unlike Scythes, the first part of the aragami that they touch is the only part that they will hit. And most aragami parts are resistant to one or more types until broken. You position yourself to have the sword hit the weak part first when it swings (the ones that hit orange or a flashy silver), so it does more damage. Hitting the parts that just spark a little does negligible damage, even with charge.


You need to set yourself to strike, and know when you can do this.

• Most aragami have a window in which they will be still after a move, or a set of moves. You can use that window to deliver a charged attack.
  
• Charging does great damage, but if you can step in, do a quick swing in a weak part and step out continuously you may have more chances to damage it in the same amount of time. This is the best strategy if you don't know yet how to do Charge well.
  
• If you notice the aragami will be still for long enough or is turned to another NPC/Player you can position to charge on it's weak part.
  
• Never be afraid to jump. I is frustrating that it only hits once in the air, but with jump and double jump you can reach weaker parts to hit and break, like Borg Calmanm's prickle and Sariel's head.

About the Parrying uper, it is great, and it isn't.

• It needs great timing to be used as a counter, but if you can pull it off and is using a Tower Shield you will barely see your HP go down.
  
• Using it to do continuous combos is good if it hits the weak parts, if not you're mostly wasting stamina.
  
• But the continuous combo is great to build up Oracle reserves, so if you're down on ammo and need to shoot go for it.

About choosing the best weapon: just check how much Slash or Crush damage they do, and what element they have, then choose them according to the Attribute weakness the aragami have or how many parts of it are weak against the kind of damage the sword does.

If you want a single best weapon to use to keep the skills you gathered, just get the one with the most damage type you want because you can do Attribute (elemental) damage with Guns just as fine, actually much better than with melee.