Conjure Ferrofluid

You summon a 10 foot sphere of magnetic fluid within range. As an action, you can either move the fluid up to 40 feet in any direction in any shape, through cracks, around objects etc, or choose one of the follow options below. The fluid must remain connected to itself, cannot be divided, and if divided will attempt to reconnect with itself. For the purposes of extinguishing fires, breathing creatures, and flowing physics, the ferrofluid behaves like water or a thin mud. If you move the ferrofluid beyond range, the spell ends.

Magnetic Attraction. You cause any metallic objects that aren't tied down, or affixed, within 60 feet of the ferrofluid to hurtle towards it. If a creature is holding on object, it must succeed on a strength saving throw to retain the object. Creatures in metallic armor may attempt a strength saving throw, resisting being drawn on a successful save. Creatures in the trajectory of any object that weighs a pound or more must succeed on a dexterity saving throw or take 1d4 points of bludgeoning, slashing, or piecing damage (whichever is most appropriate) for every pound the object weighs. Hurtling objects maneuver around stationary objects and other impediments, but otherwise take the most direct path towards the ferrofluid, sinking into it upon arriving.  Objects magnetized by the ferrofluid remain suspended in and around it as long as you only either move the ferrofluid or choose this feature again. 

Magnetic Repulsion. You cause any metallic objects within 20 feet of the ferrofluid that aren't affixed to be repelled from it. Each object travels up to 20 feet directly away from the ferrofluid. Creatures in the trajectory of any object that weighs a pound or more must succeed on a dexterity saving throw or take 1d4 points of bludgeoning, slashing, or piecing damage (whichever is most appropriate) for every pound the object weighs. If a creature is holding on object, it must succeed on a strength saving throw to retain the object. Creatures in metallic armor may attempt a strength saving throw, resisting being repelled on a successful save. This effect doesn't continue unless you use your action to continue it.

Corrode. You cause the ferrofluid to corrode any non-precious, nonmagical metal it is in contact with. Weapons become useless, metal structures and objects take 4d8 points of acid damage, and the AC bonus provided by armor is reduced 1d4. Small metallic objects simply disintegrate. This effect doesn't continue unless you use your action to continue it.

Ferrofluid Armor.  You cause the fluid to envelop you. You gain a bonus to your armor class equal to your spellcasting modifier, resistance to acid, bludgeoning, slashing, and piercing damage, and weakness to lightning damage. You move with the ferrofluid if you use you action to move it, but otherwise, you movement speeds are reduced by 30 feet. Additionally, you have disadvantage on dexterity saving throws, and any attacks, that would cause you to take lightning damage are made with advantage, and any effects or spells that require you to save against lightning damage force you to roll with disadvantage. You can extricate yourself from the ferrofluid when you choose another effect, or as a bonus action.