Why, hello there! Thanks for viewing this map! In this world, you can choose the properties of arrows. You can summon Fireballs, TNT, the Wither Boss (with no AI) and much more just by shooting an arrow! And even better, you can use more than one at a time!
Simply throw a Snowball to kill the arrows or spawn a Wolf to kill all entities. When you want to change the properties, click "Reset Arrow" first.
Feel free to copy the redstone involved and put it in your map if you would like to. Make sure you change the coordinates though and credit me please haha. Have fun and thanks a bunch for the support!