Just some random ideas

First: Obsidia, modified Latin for blockade. Places a 2x2 of barriers, does not replace other blocks, just air. Constantly blocking doors/trolling will be punishable, can go to 4x4 and last for 2 minutes (starts as 10 seconds). Movements: Swish up to the left, Swish down to the right, Swish down to the left. Backfire: You will be trapped. Year: 3

Second: Devovea, modified Latin for sacrifice (in the way of devoting yourself), takes 3 hearts from you to completely conceal their wounds and fill them with power (Resistance). When first casted, it takes 4 hearts, and works down to 3, along with the resistance timer. Swish up to the left, Swish down to the right, Swish down to the right. Backfire: Only self harm. Year: 2

Third: Adiuuat, modified Latin for vaporize. Temporarily makes a 2x2x4 tunnel through all water. Will cave in after a while. Eventually does a 4x4x7 of water, and stays for 2 minutes. Year: 4  

Do whatever with these.

The last one is impossible.  I can't make water do something special in minecraft the gravity is not in the api and it would be hours (maybe days) of work looking for it in nms.

Ah, ok. I was just thinking of an effect similar to sponge, like possibly make Sponge invisible, and place it for a split second? Then update the water a bit later? That was what I was thinking, but if it is impossible, so be it.