Minecraft Java Edition – How to Modify Attack Speed NBT in Minecraft 1.16

Adding Tags to the item will not be set as the entity's Tags data. All the item data itself will be lost except for Potion and CustomPotionEffects, which are copied to the arrow entity if existent.

Tipped arrows will be necessary, but you can apply custom effects to reduce any issues should it strike a player or mob, such as setting the duration to 0. Currently the Instant Healing effect does not function on tipped arrows, but you may need to switch to something else should it work in the future.

The amplifier would be how you'd differentiate arrows from one another.

Example arrows to provide:

/give @p minecraft:tipped_arrow 64 0 {CustomPotionEffects:[{Id:6b,Duration:0,Amplifier:0b}]}

/give @p minecraft:tipped_arrow 64 0 {CustomPotionEffects:[{Id:6b,Duration:0,Amplifier:1b}]}

Then you'd label those arrows based on the effects it has, with the amplifier making each one unique:

/scoreboard players tag @e[type=Arrow,tag=!tntarrow] add tntarrow {CustomPotionEffects:[{Id:6b,Duration:0,Amplifier:0b}]}

/scoreboard players tag @e[type=Arrow,tag=!custom2] add custom2 {CustomPotionEffects:[{Id:6b,Duration:0,Amplifier:1b}]}

And finally, target based on that label:

/say @e[type=Arrow,tag=tntarrow] is a "tntarrow".

Questions One & Two

There is a way to do this but without the entitydata command, rater than modify the entity's damage and health that way with a skeleton it is easier to give them an enchanted bow or a bow with attribute modifiers.

Skeletons

The following command will give all skeletons in the world a bow that makes their health 200% of it's original and slightly more damage. This also makes the shot more powerful and sets the arrow on fire because of the punch and flame effects applied.

/replaceitem entity @e[type=skeleton] slot.weapon minecraft:bow 1 0 {AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:20,Operation:1,UUIDLeast:398320,UUIDMost:481485},{AttributeName:"generic.attackDamage",Name:"generic.attackDamage",Amount:2,Operation:1,UUIDLeast:124027,UUIDMost:199291}],ench:[{id:49,lvl:10},{id:50,lvl:1}]}

Blazes

This is harder but still doable thanks to the attribute modifiers on stuff. This also makes the blaze drop a little more blaze rods because it is technically wearing a blaze rod:

/replaceitem entity @e[type=blaze] slot.armor.chest minecraft:blaze_rod 1 0 {AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:20,Operation:1,UUIDLeast:398320,UUIDMost:481485},{AttributeName:"generic.attackDamage",Name:"generic.attackDamage",Amount:2,Operation:1,UUIDLeast:124027,UUIDMost:199291}]}

The rest can all be done using MC Stacker which gives you the commands if you specify the attributes you want to add using the format established.

Question Three

Place command blocks in a central location and then perform these commands using chained command blocks to spawn aggressive giants at the push of a button randomly thought the world (Also They Have Laser Eyes):

/summon guardian ~ ~1 ~ {Attributes:[{Name:generic.attackDamage,Base:100},{Name:generic.followRange,Base:100}],Silent:1,ActiveEffects:[{Id:14,Amplifier:1,Duration:200000,ShowParticles:0b}],Passengers:[{id:"giant"}]}
/spreadplayers ~ ~ 1500 10000 false @e[type=Giant,r=10]

Question Four

I tested this with the attribute modifier method and the answer seems to be no but this may depend on the operation type of the modifier.