How would I go about making an AI that chases and kills you around obstacles?

if you want path finding, do this and put a value and name it Target

debugMode = false
targetNPCs = false

--

h = script.Parent.Parent:WaitForChild("Humanoid")
pathService = game:GetService("PathfindingService")
targetV = script.Parent:WaitForChild("Target")

function closestTargetAndPath()
    local humanoids = {}
    if targetNPCs then
        local function recurse(o)
            for _,obj in pairs(o:GetChildren()) do
                if obj:IsA("Model") then
                    if obj:findFirstChild("Humanoid") and obj:findFirstChild("Torso") and obj.Humanoid ~= h and obj.Humanoid.Health > 0 and not obj:findFirstChild("ForceField") then
                        table.insert(humanoids,obj.Humanoid)
                    end
                end
                recurse(obj)
            end
        end
        recurse(workspace)
    else
        for _,v in pairs(game.Players:GetPlayers()) do
            if v.Character and v.Character:findFirstChild("HumanoidRootPart") and v.Character:findFirstChild("Humanoid") and v.Character.Humanoid.Health > 0 and not v:findFirstChild("ForceField") then
                table.insert(humanoids,v.Character.Humanoid)
            end
        end
    end
    local closest,path,dist
    for _,humanoid in pairs(humanoids) do
        local myPath = pathService:ComputeRawPathAsync(h.Torso.Position,humanoid.Torso.Position,500)
        if myPath.Status ~= Enum.PathStatus.FailFinishNotEmpty then
            -- Now that we have a successful path, we need to figure out how far we need to actually travel to reach this point.
            local myDist = 0
            local previous = h.Torso.Position
            for _,point in pairs(myPath:GetPointCoordinates()) do
                myDist = myDist + (point-previous).magnitude
                previous = point
            end
            if not dist or myDist < dist then -- if true, this is the closest path so far.
                closest = humanoid
                path = myPath
                dist = myDist
            end
        end
    end
    return closest,path
end

function goToPos(loc)
    h:MoveTo(loc)
    local distance = (loc-h.Torso.Position).magnitude
    local start = tick()
    while distance > 4 do
        if tick()-start > distance/h.WalkSpeed then -- Something may have gone wrong. Just break.
            break
        end
        distance = (loc-h.Torso.Position).magnitude
        wait()
    end
end

while wait() do
    local target,path = closestTargetAndPath()
    local didBreak = false
    local targetStart
    if target and h.Torso then
        targetV.Value = target
        targetStart = target.Torso.Position
        roaming = false
        local previous = h.Torso.Position
        local points = path:GetPointCoordinates()
        local s = #points > 1 and 2 or 1
        for i = s,#points do
            local point = points[i]
            if didBreak then 
                break
            end
            if target and target.Torso and target.Health > 0 then
                if (target.Torso.Position-targetStart).magnitude < 1.5 then
                    local pos = previous:lerp(point,.5)
                    local moveDir = ((pos - h.Torso.Position).unit * 2)
                    goToPos(previous:lerp(point,.5))
                    previous = point
                end
            else
                didBreak = true
                break
            end
        end
    else
        targetV.Value = nil
    end
    if not didBreak and targetStart then
        goToPos(targetStart)
    end
end

i have fixed your code it may be a bit laggy

local runSpeed = 28
local pathService = game:GetService("PathfindingService")
local humanoid = script.Parent.Humanoid
humanoid.Parent.PrimaryPart:SetNetworkOwner(nil)

humanoid.WalkSpeed = runSpeed

function findNearestTorso(pos)
    local list = game.Workspace:children()
    local torso = nil
    local dist = 800
    local temp = nil
    local human = nil
    local temp2 = nil
    for x = 1, #list do
        temp2 = list[x]
        if (temp2.className == "Model") and (temp2 ~= script.Parent) then
            temp = temp2:findFirstChild("HumanoidRootPart")
            human = temp2:findFirstChild("Humanoid")
            if (temp ~= nil) and (human ~= nil) and (human.Health > 0) then
                if (temp.Position - pos).magnitude < dist then
                    torso = temp
                    dist = (temp.Position - pos).magnitude
                end
            end
        end
    end
    return torso
end

local path

while true do
    wait(0.5)
    local target = findNearestTorso(script.Parent.HumanoidRootPart.Position)
    if target ~= nil then
        path = pathService:CreatePath()
        path:ComputeAsync(script.Parent.HumanoidRootPart.Position, target.Position)

        local waypoints = path:GetWaypoints()

        if path.Status == Enum.PathStatus.Success then
            for i,v in pairs(waypoints) do
                local part = Instance.new("Part", workspace)
                part.Anchored = true
                part.CanCollide = false
                part.Material = Enum.Material.Neon
                part.Position = v.Position
                part.Size = Vector3.new(0.6,0.6,0.6)
                part.Shape = "Ball"



                if v.Action == Enum.PathWaypointAction.Jump then
                    humanoid.Jump = true
                end 
                humanoid:MoveTo(v.Position)
                humanoid.MoveToFinished:Wait()
            end
        end
    end
end

hope you like it