So I saw that art and it gave me the idea about spear(s) as an ingame weapon. I'm not a tallanted artist/3d modeller, so you won't have a design from me, but Uunimods art is pretty good.
On the idea. The spear will deal piercing damage and will have a 3 hit combo. A wide swing that doesn't move player, lunge forward that moves the player half/full block and the third hit is a 360 degrees spin that doesn't move/moves player half a block. The charge will be one powerfull lunge forward that moves the player 2/3 blocks and as the knight thrusts out the spear, 2 slightly smaller spears appear next to it (all do the same damage). You drag all the enemies you hit with you and at the end of the combo they get a middle-sized knockback. Also you deal damage during the whole movement.
If OOO decides to use the amazing design that Uunimod created. With the little coloured parts at the top of the spear, the different types of spears could have different effect. Blue light for normal damage spear with higher damage output than the others, red light for fire green/yellow/whitish-blue/slightly brighter blueish for poison/stun/freeze/shock spears. The effect ones as I stated have less damage output than the normal one to compensate for the effect.
That's all I can think of now, but if you have any questions/ideas, please post them :)
Is it meant to add a little defense to the last hit of the combo?
As for the charge,I say it should only work with the smaller AND mobile enemies, with the initial damage doing up to 150% a hit.
I'm against having multiple versions of a weapon unless its a specialized-normal set.We shouldn't have that much variation,the weapon's status should reflect how the weapon works.In this case,I vote for poison.