I'll get straight to the point, there are three rare monsters that you can currently see (or that I have seen) the love puppy, imposto cubes, and mew cat.
First of all there not a challenge so it just make them a relief to see.
Out of all of them the love puppy is the only one with valuable drops (when it drops some thing that is).
So I think it would be great to add some new rare monster that are very powerful and have the chance of a rare drop.
Here are some ideas:
-a cursed greavers: they would have the chance of inflicting a curse status ailment just as much as any other greaver deals any status other ailments. They would also have other attack such as shooting long range curse bullet (not the way the do when attacking but like gun puppies), they would have quick dash attack in which they quickly fly through knights (knights can get caught in the knock back a get hit multiple times). It would also have 3 times more health than most greaver and take a whole tier less of damage. (tier 3 exclusive)
Rewards: cursed greaver wings
- a dual wielding trojan: So instead of giving dual wield to knights, I think it would be better to do the opposite and give it to enemies instead. The trojan will have no shield but it will have a much higher defense and HP. Behavior wise it will be for more aggressive than regular trojans, there attacks will consist of 3 hits and they would have a charge attack similar to the levi's.
Rewards: trojan sword or armor (their star rating wil depend on the tier aquired from).
a nova cube:
It would look like the bast cubes except they would have spikes around them and a shocking aura and it would be a very dark blue.
Their attacks would consist of ground spike attacks (that can shock you), a spin attack similar t the jk's tantrum attack (except it is not invincible when using it) and the standard tackle. When it dies... lets say it put the ultra blast cube to utter shame. The explosion would be the size of 5 star bomb and have the knock back of the BaB and would then leave a haze (5 star radius) the can inflict fire and shock that last 10 seconds. And thats not all when jelly die it want to take every one with it so during the three seconds it would take to detonate it sucks up every thing with in shooting range (but slowly and not that powerful suction , player who run in the opposite direction would run as fast as if they where stunned (a possible tactic to avoid the explosion would be to ram it with a levi charge ).
rewards: blast cube armor/helm (may be either a cosmetic or an actual piece of gear). If an actual piece of gear it would start off as blast cube (2 star) and can be upgrade to super blast cube then ultra and finally nova (not sure about the stats though).
Cursed Greavers will kill the game but yeah, they'd be pretty boss to fight.
The rewards could be...
I can't think of anything besides Greaver Wing accessories, and it's fairly obvious OOO will keep cool stuff like that as CE promos or for p2pers only