Vile striker: http://wiki.spiralknights.com/Vile_Striker
4* fast sword with a 5/10 hit combo, and it poisons. Finishing your attack quicker means you can block quicker too.
Asking price: 1.9k CE

Winmillion: http://wiki.spiralknights.com/Winmillion
4* sword that shoots projectiles on every swing
Asking price: 1.5k CE

Stone Tortoise: http://wiki.spiralknights.com/Stone_Tortoise
4* shield with massive durability.
Asking price: 700 CE

In game name: Kalign