What symbol or item could be used to represent Cassius's qualities in Julius Caesar?

In Shakespeare's Julius Caesar, Cassius possesses much aplomb as well as a duality to his personality, so, prehaps, he can be symbolized by a sword.  In the first act of the play, like a new, shiny weapon, Cassius seduces Brutus into joining the conspirators against Caesar--Act I, Scene 2 has, in fact, been called "the seduction scene."   Then, in the next scene, Cassius with drawn sword as a phallic symbol, declares his manliness in challenging the gods as he walks about the streets during "the perilous night" that has much thunder and lightning.  He criticizes the fearful Casca:

You are dull, Casca, and those sparks of life/That should be in a roman you do want,/Or else you use not. (I,iii,

Similarly, with Brutus in the previous scene, Cassius has  shown his disdain for the heavens as he tells Brutus,

Men at some time are masters of their fates:/The fault, dear Brutus, is not in our stars,/But in ourselves, that we are underlings. (I,ii,139-142)

That he finds use for his sword is evident in the third act of Julius Caesar as Cassius uses his sword to slay Caesar and suggests that Marc Antony be slain, as well, thus eliminating anything dissenters against their rule.  This advice proves to be wise; however, Brutus does not follow it, reasoning that the crowd will understand his motives.

Later in the play, it is Cassius who acquiesces to Brutus--even against his better judgment.  Critics say that Cassius loves Brutus and wants to be thought honorable like Brutus, so he listens to his friend.  It is in Act IV that Brutus and Caesar argue: the sword turns to its other edge, as it were. For, Cassius becomes the more reasonable one.  Brutus refuses to wait and let his troops rest at Phillippi, declaring that

There is a tide in the affairs of men/Which, taken at the flood, leads on to fortune;/Omitted, all the voyage of their life/Is bound in shallows and in miseries./On such a full sea are we now afloat,/And we must take the current when it serves,/Or lose our ventures. (IV,iii,244-250)

In a strange turn of character, Cassius puts away his sword of bravado and military acumen, and falls prey to supersitition.  Once a Rationalist and an Epicurean who did not believe in the stars, as he has told Brutus, Cassius now speaks of the presence of omens and hopes that the gods "will be friendly" (V,i,93).  His vision of what happens in the battle distorted by his "sight ever thick" (V,ii,21), his sharp sword serves only as the weapon for him to have an honorable death, rather than being taken prisoner.  The sword is taken out, but the second edge is used, his symbol turned upon himself.