What is the best way to kill Skeletron Prime in Terraria?

Here's what I did for my first win against him.

1. Hung out in the hallow and underground hallow to get a) Pixie dust b) Unicorn Horns c) Souls of light

2. Made a few hallowed mimics to kill (chest + key of light - made from souls of light). Until I got a Daedulus bow.

3. Made holy arrows from the pixie dust and unicorn horns. (I made about 1K, but that was overkill)

4. Horizontal sky arena from two parallel platforms spaced a double jump apart. Quite long. Put a heart statue at one end and heart lanterns and camp fires placed along it.

5. Summon and rain holy arrows down on him.

6. Switched to different weapon when only head was left (I used yoyo but use whatever floats your boat.)

It was pretty safe and pretty quick. Just run back to the heart statue to get healed.

Used the same arena / strategy for all three mechanical bosses, worked pretty well in all cases.

Wasn't using anything amazing something like - Oraculum armor, obsidian shield, some basic wings (not really needed) and lightning boots - not even all reforged.

I killed Skeletron Prime with the Clockwork Assult Rifle. The the gun is a pretty rare drop from the Wall Of Flesh. The bullets that work best are cursed bullets and crystal bullets. The crystal bullets are slightly better because they can explode into shards. The shards will deal damage to the 4 limbs that are spinning around him. The cursed bullets will set fire to skeletron prime and will do 1 damage per millisecond for around 20 seconds. But the clockwork assult rifle is a good gun to save ammo. The minishark also works but isn't the best as it gets rid of the bullets way too fast. The clockwork rifle will turn one bullet into three. You don't really need a platform to kill skeletron prime because i play on the 3ds version. The 3ds version will let you target the enemy so when i do that all i have to do is to jump and press the attack button. I used demon wings but any wings are ok. so just start to fire those crystal bullets and youll kill skeleton prime in no time at all.

I have an interesting tactic to battle Skeletron Prime so I might as well share it here.

Equip

1. Daedalus Stormbow
2. Holy Arrow
3. Ichor/Cursed Arrow
4. Any hardmode range armour, use sets with reduce ammo consumption if holy arrow is limited.
5. Any wing, easier if using those with highest vertical reach.
6. Health Potions - always bring some in case, bring more if you are not confident
7. Magic Quiver,Ranger Emblem - optional but helps

Reforging accessories to Warding prefix will give a total of 20(24 for expert) which helps a lot.

Any combat buff potion will help as long as you have it and want to use it here.

Arena

Only a single layer of platform is needed, build it more than 15 tiles above ground to maximise effect. Place as many Heart Statues wired to Trigger Plates, if less than 3 status are available, wire them(it) to a one second timer to generate as many hearts as possible during the fight.

Build a vertical rope upwards from the platform - I suggest rope since it is easiest to obtain, but any means to reach upwards is okay as long as it is not solid blocks. Place Campfire and Heart Lantern to cover as much area vertically as possible.

Fight

Hit with Ichor/Cursed Arrow first, once Skeletron Prime closes in on you, fly upwards - you may occasionally stop flying momentarily to increase air time but don't overdo it. While going up, use Holy arrows. Most of the arrows and stars will hit, doing large amount of damage.

Once you run out of flight, DO NOT slow fall. Drop as fast as you can to avoid getting hit this will buy time for potion cool down. While you are falling you can still use Ichor/Cursed Arrow to do some damage.

Once you reach the platform, grab all the Hearts from the statue(s) to heal and repeat the process all over.

During the change of direction, if you see the Head spinning or starting to spin, Do Not attempt to charge through, avoid it from the side and return to vertical combat. Alternatively you can charge into its Arms and go through the head during the immunity period but that is risky and I would not suggest.

If you find yourself fast enough you can switch between Ichor and Holy Arrows to maximise dps. Otherwise just use Holy Arrows purely.

Same tip as any boss fight - Do Not just use health potions when you are about to die, use it as long as it cannot heal you beyond full health. That will greatly increase your chances of survival.

To start, I suggest bringing your Daedalus Stormbow, along with holy or unholy arrows. If you are a magic user, I suggest getting all of your fallen stars, and turn them into mana stars to boost up your max mana. I also recommend using the following magic books; cursed, Ichor, or crystal storm, because they can do a good amount of damage. Make sure you have your armor (hallowed, palladium, or titanium amour) to help you in battle. Try to take on the destroyer first, then make more damaging weapons with his souls.

What I did? I killed the destroyer first (with my cutlass) and got the megashark/light discs. Then I used my new weapons and hallowed armor to kill the twins. With my souls of sight, I made a rainbow rod. It took a few tries, but with all of the appropriate gear (cursed bullets recommended) He died. Then I wasted the souls of fright left over from crafting the drax on a flamethrower.

the easiest arena is having 2 layers of platforms 50 blocks apart for wings to fly through. Have a hook as well just in case you can't fly up. Have heart lanterns, campfires, heart statues to provide healing.

For melee i either use chain guillotines or ice sickle with titanium armor with power glove, warrior emblem, and some buffs like wrath, lifeforce, regen, rage, well fed.and also have the sharpen table for armor pierce

for range its easiest with daedlus stormbow and titanium armor ez win. maybe archery potion but ya thats it and clockwork assult rifle for head.

for mage its either crystal serpent, crystal storm, sky fracture with golden shower/cursed flames. You can bring titanium or forbiden armor.You should also have magoc power potions, magic regen, mage emblem.

For summoner i recommend defeating twns first getting the optic staff and killing prime with it. You should have summoner potions and spider armor. You should also have the bewitching table for +1 minion and also some wrath potions and summoner emblem

You should have well fed as buff, a minion(imp, twins, pirate) a sentry(queen spider) and wings, boots(lighting or frostpark), shield(cobalt/obsidian),