Added ability for Stalinium Sword to grant speed and resistance effects to player and nearby allies.

src/main/java/net/krituximon/stalinium/item/StaliniumSwordItem.java

@@ -1,6 +1,7 @@
 package net.krituximon.stalinium.item;
 
-import net.minecraft.world.entity.Entity;
+import net.minecraft.world.InteractionHand;
+import net.minecraft.world.InteractionResultHolder;
 import net.minecraft.world.entity.LivingEntity;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.effect.MobEffectInstance;
@@ -8,13 +9,22 @@ import net.minecraft.world.effect.MobEffects;
 import net.minecraft.world.item.SwordItem;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Tier;
+import net.minecraft.world.item.UseAnim;
 import net.minecraft.world.level.Level;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.phys.AABB;
+import net.minecraft.world.phys.Vec3;
 
 import java.util.List;
 
 public class StaliniumSwordItem extends SwordItem {
+    private static final double RANGE = 6.0;
+    private static final double HALF_ANGLE = Math.toRadians(30);
+    private static final double COS_HALF_ANGLE = Math.cos(HALF_ANGLE);
+    private static final int DURATION = 5 * 20;
+    private static final int SPEED_AMP = 1;
+    private static final int RESIST_AMP = 0;
+
     public StaliniumSwordItem(Tier tier, Properties props) {
         super(tier, props);
     }
@@ -37,6 +47,35 @@ public class StaliniumSwordItem extends SwordItem {
         return super.hurtEnemy(stack, target, attacker);
     }
 
+    @Override
+    public InteractionResultHolder<ItemStack> use(Level world, Player player, InteractionHand hand) {
+        if (!world.isClientSide) {
+            player.addEffect(new MobEffectInstance(MobEffects.MOVEMENT_SPEED, DURATION, SPEED_AMP, false, true));
+            player.addEffect(new MobEffectInstance(MobEffects.DAMAGE_RESISTANCE, DURATION, RESIST_AMP, false, true));
+            AABB area = player.getBoundingBox().inflate(RANGE);
+            List<Player> allies = world.getEntitiesOfClass(
+                    Player.class, area,
+                    p -> p instanceof ServerPlayer && player.isAlliedTo(p)
+            );
+            Vec3 look = player.getLookAngle();
+            for (Player ally : allies) {
+                Vec3 toAlly = ally.position().subtract(player.position()).normalize();
+                if (toAlly.dot(look) >= COS_HALF_ANGLE) {
+                    ally.addEffect(new MobEffectInstance(MobEffects.MOVEMENT_SPEED, DURATION, SPEED_AMP, false, true));
+                    ally.addEffect(new MobEffectInstance(MobEffects.DAMAGE_RESISTANCE, DURATION, RESIST_AMP, false, true));
+                }
+            }
+        }
+        player.startUsingItem(hand);
+        player.swing(hand, true);
+        return InteractionResultHolder.sidedSuccess(player.getItemInHand(hand), world.isClientSide);
+    }
+
+    @Override
+    public UseAnim getUseAnimation(ItemStack stack) {
+        return UseAnim.BOW;
+    }
+
 
     @Override
     public boolean isDamageable(ItemStack stack) {