My new idea of a mod I will be working on

me and my friend talked about an idea for a mod called Hardcraft (hope it doesnt already exist)
basically, the main premise is that the game will be split up into two parts
one is pre-hardmode (the more vanilla mc part of the mod) and hardmode, which is only activated after you beat the ender dragon (it becomes harder, but new items get the ability to be made/found and more mobs/bosses can spawn)
the only ideas as of now relating stuff like mobs are these

an event of sorts called the "windy monsoon" 
it can occur on both pre-hardmode and hardmode (until i find a way to make it happen only in hardmode)
its a type of thunderstorm but with unique and dangerous mobs, and one punishing boss (if in pre-hardmode)
mobs:
lightning blitzer: a knight with a lightning sword, is strong but slow
thunder geist: a floating energy of lightning, can strike enemies with bolts of electricty while flying
aqua grounddiver: a huge water worm like entity that can go under the ground and strike from below
charge hedgehog: a much stronger cousin of sorts to the sliverfish
the boss:
ocean deverator: a huge creature, has three attacks: one where it shoots rapid bolts of electricty, another where it shoots out bubbles and if your hit, it gives the bubble drowning effect and slowness, and a melee attack where it pierces you with its tendrils
ill update you later when theres more stuff/stuff gets finished, ill release the first pre-alpha version when its stable enough and when theres enough stuff