This mod adds poweful end game items, being them:
-Nova's Tear;
-Nova's Gem;
-Nova's Core;
-Nova's Blade;
-Nova's Pickaxe;
-Nova's Multitool;
-Nova's Armor Set;
-Charged Nova's Core;
-Charged Nova's Blade;
-Charged Nova's Pickaxe;
-Charged Nova's Multitool;
-Charged Nova's Armor Set.
They can be obtainned by completing some steps. First you need to get Nova's Tear by mining, finding in chests or trading with an Armorer Villager. Then, you can combine it with gold to make Nova's Gem, and then use it to make Nova's core, which is a very powerful item, that gives you many buffs and can be used as a weapon. Now, you can make Nova's Blade, Pickaxe and Armor Set.
There also are the Charged variants of the Nova's Core, Blade, Pickaxe and Armor Set obtained by combining a base Nova's Core with two nether stars and two nova's gems. Then you can use the base core and the charged core to make the charged variation off all other items.
They impact the gameplay by making it so that if the player wants powerful weapons, to make them stronger and generally a harder target, they can do it by obtaining these items. These might also be useful in multiplayer maps/servers where players might try to kill you, because these items will make it very hard to.