Calibur is an excellent sword because it deals good damage to all monsters and has one of the best charged attacks (360 swipe) so I suggest you keep it and upgrade it to a Leviathan Blade. But if you want special damage to each kind of monster, I suggest you craft other swords that deals a specific type of damage. For Elemental damage either get the Avenger line(starts from the Sealed Sword Line) or the Fireburst/Iceburst line(starts from Brandish). For Shadow damage get the Nightblade line(starts from Brandish) or the Faust line(starts from Sealed Sword Line). For Piercing damage get either the Flourish line or the Snarble Barb line(10 Snarbolax Tokens)
Links to the wiki:
http://wiki.spiralknights.com/Leviathan_Blade
http://wiki.spiralknights.com/Avenger
http://wiki.spiralknights.com/Brandish
http://wiki.spiralknights.com/Faust
http://wiki.spiralknights.com/Flourish
http://wiki.spiralknights.com/Snarble_Barb

Blaster is ok but I suggest you to get a elemental gun as Constructs are weak to it and sometimes you want to attack them from a distance. Get an Alchemer (not the Prismatech one) or Silversix(starts from Antigua). For guns that deals Shadow damage, get either the Shadowtech Alchemer or Blackhawk(starts from Antigua). For Piercing damage get the Antigua line, Magnus line or the Needle Shot line.
Links:
http://wiki.spiralknights.com/Firotech_Alchemer
http://wiki.spiralknights.com/Cryotech_Alchemer
http://wiki.spiralknights.com/Voltech_Alchemer
http://wiki.spiralknights.com/Antigua
http://wiki.spiralknights.com/Magnus
http://wiki.spiralknights.com/Needle_Shot

Cobalt is not a very good armor so i suggest that you drop it. Get other armors instead like the Wolver line. Because there are too many available armors I am just going to give you the link to armor in general.
Link:
http://wiki.spiralknights.com/Armor
http://wiki.spiralknights.com/Helmet