§ How to · with Picoo
How to make a Roblox katana combat system (anime style)
By Sametcan Tasgiran, Founder & Developer·Published ·Updated
Anime combat games — Demon Slayer-style katana fighters especially — need two things working together: a katana that actually equips in the player's hand and glows, and a combo/block/parry/dash system that feels sharp. Picoo generates both: sword_tool for the weapon, combat_system for the mechanics.
sword_tool (glowing katana + trail) + combat_system (combo/block/parry/dash) · two recipes · server-authoritative.
Equipping katana (fixed grip)
The Tool ships with a correctly-configured Handle — CanCollide off, Massless on, Grip set — so it actually sits in the hand. This is the #1 bug hand-built weapons hit.
Glowing element blade
Pass element: fire / ice / void / lightning / shadow / holy for a Neon themed blade, a PointLight aura, streaming particles, and a swing trail — the trendy anime-blade look, all code, no uploaded assets.
Swing trail on M1
Two attachments down the blade drive a Trail that flicks on during the swing and off after — the signature ribbon behind every katana slash.
Procedural cinematic swing
swing_style: procedural arcs the blade through a slash via Tool.Grip plus an arm follow-through — a code-driven swing for when you can't upload a keyframe animation.
Full combat mechanics
combat_system layers an M1 combo, heavy, block, parry window, and dash on top — server-authoritative and exploit-safe.
No uploaded assets required
Every visual — glow, particles, trail, swing — is generated in code. No mesh upload, no animation upload, no moderation wait.
Files Picoo ships for this prompt
6 files · 300 lines · about a minute · 10 credit
StarterPack/Katana (Tool + Handle)
Equipping Tool with a configured Handle and Grip
instance
StarterPack/Katana/KatanaLocal.lua
Builds glow/trail/particles at load; swings and toggles the trail
70 lines
ServerScriptService/KatanaServer.lua
Server-validated swing damage and hit VFX
84 lines
ServerScriptService/CombatSystem/*
Combo, block, parry, dash, stamina, hitbox
214 lines
Sample output: StarterPack/Katana/KatanaLocal.lua
--!strict
-- StarterPack/Katana/KatanaLocal.lua (Picoo · element = "fire")
-- Every visual is built in code at load — no uploaded mesh or animation.
local Tool = script.Parent
local Handle = Tool:WaitForChild("Handle")
Handle.Material = Enum.Material.Neon
Handle.Color = Color3.fromRGB(255, 90, 20)
local aura = Instance.new("PointLight")
aura.Color = Color3.fromRGB(255, 120, 40)
aura.Range = 11
aura.Brightness = 3
aura.Parent = Handle
-- swing trail: two attachments down the blade's long axis, off at rest
local a0 = Instance.new("Attachment"); a0.Position = Vector3.new(0, 0, -2.5); a0.Parent = Handle
local a1 = Instance.new("Attachment"); a1.Position = Vector3.new(0, 0, 2.5); a1.Parent = Handle
local trail = Instance.new("Trail")
trail.Attachment0, trail.Attachment1 = a0, a1
trail.Lifetime = 0.3
trail.Color = ColorSequence.new(Color3.fromRGB(255, 90, 20))
trail.LightEmission = 1
trail.FaceCamera = true
trail.Enabled = false
trail.Parent = Handle
Tool.Activated:Connect(function()
trail.Enabled = true
task.delay(0.35, function() trail.Enabled = false end)
end)Building a Roblox katana combat system (anime style)
Anime combat games are one of the biggest and fastest-growing genres on Roblox, and the katana is their signature weapon. Two problems stop most developers cold: the katana won't stay in the player's hand, and there's no way to get that glowing, trailing, "burning" blade look without a modeling pipeline. Picoo solves both in code.
The equip problem is almost always the Handle. A Roblox Tool equips by welding a child part named exactly "Handle" to the character's hand. If that Handle has CanCollide on, the physics fight the weld and the weapon flies off or never appears. Picoo's sword_tool recipe ships the Handle with CanCollide = false, Anchored = false, Massless = true, and a configured Grip, so the katana seats in the hand every single time — no manual weld debugging.
The look is pure code. Pass element: 'fire' and sword_tool sets the blade Material to Neon with a themed colour, parents a PointLight for the aura, adds a streaming ParticleEmitter, and builds a Trail from two attachments down the blade — enabled only during the swing so you get the ribbon behind each slash. Because it's all Instance.new at load, there is no mesh upload and no animation upload, which means no moderation wait and nothing that can get flagged. It appears the instant the tool loads.
Real keyframe animation is the one thing code genuinely cannot produce — uploading a KeyframeSequence to Roblox is a moderated asset operation. Instead Picoo animates the swing procedurally: it arcs the blade through the slash by tweening Tool.Grip and adds an arm follow-through on the shoulder's Motor6D. It is wrapped so it can never throw a runtime error, and it works identically for every player without any upload.
For a complete anime fighter, stack the combat_system recipe on top: an M1 combo chain, a heavy attack, a block, a parry window that stuns the attacker, a dash with invincibility frames, and stamina — every damage calculation on the server. sword_tool makes the katana look and equip right; combat_system makes fighting with it feel right.
See more on the Luau generator, the game builder, or browse the full blog.
Frequently asked
Why won't my katana appear in the player's hand?+
Almost always the Handle collides or is missing a Grip. A weapon Tool needs a BasePart child named exactly 'Handle' with CanCollide = false, Anchored = false, Massless = true, and a sensible Tool.Grip. Picoo's sword_tool recipe sets all of these, so the katana equips correctly every time.
Can Picoo make a real cinematic katana animation?+
A real uploaded keyframe animation needs a Roblox asset upload (moderated) that code cannot do. Instead Picoo animates the swing procedurally — arcing the blade via Tool.Grip plus an arm follow-through with TweenService — which works for every player with no upload.
How do I get the glowing / flaming blade look?+
Pass element: 'fire' (or ice, void, lightning, shadow, holy) to sword_tool. It composes a Neon blade, a PointLight aura, element particles, and a swing trail — all generated in code, so it shows up instantly with no mesh or texture upload.
Does it come with combos and parry?+
Add the combat_system recipe. It layers an M1 combo chain, heavy attack, block, parry window (which stuns the attacker), dash with i-frames, and stamina — all server-authoritative — on top of the katana.
Is this exploit-safe?+
Yes. All damage is server-side. The client fires only swing intent; the server validates cooldown and range and applies damage. Nothing a client sends becomes a damage number.
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