diff --git a/modules/energytick.lua b/modules/energytick.lua
index 6324bd65..ce787798 100644
--- a/modules/energytick.lua
+++ b/modules/energytick.lua
@@ -1,20 +1,82 @@
-local function getAdjustedTickTimer()
-  local adjustedEnergyTick = 2
+-- One server clock drives every power: Player::RegenerateAll fires every
+-- REGEN_TIME_FULL (2s), re-arms with `+=`, and is never reset by casting. The
+-- five-second rule (SetLastManaUse on any mana-costing cast) changes what a tick
+-- pays, never when it lands; mp5 and the player's MOD_MANA_REGEN_INTERRUPT share
+-- still come in. That share can't be computed here -- item sources are equip
+-- auras absent from the buff list and m_modManaRegenInterrupt is never sent --
+-- so the spark shows it instead: dim through the window until a tick lands.
+--
+-- The sweep free-runs on that clock and phase-locks to observed gains. A gain
+-- mid-sweep (Illumination, Judgement of Wisdom, potions, a Mana Spring totem on
+-- its own phase) is not the tick and never moves it.
 
-  -- Check rogue talents and compute energy tick timing reduction for Combat spec (1.18.0 Blade Rush Talent)
-  if UnitClassBase("player") == "ROGUE" then
-    local _, _, _, _, currRank = GetTalentInfo(2, 16)
-    local bladeRushRank = currRank or 0
+local FIVE_SECOND_RULE = 5
 
-    if bladeRushRank > 0 then
-      local agility = UnitStat("player", 2)       -- 2 is agility stat index
-      local reductionPerAgi = 0.0006 * bladeRushRank -- 0.0006 for rank 1, 0.0012 for rank 2
-      local totalReduction = agility * reductionPerAgi
-      adjustedEnergyTick = adjustedEnergyTick - totalReduction
+-- gains farther than this from the predicted boundary are not the tick
+local TICK_TOLERANCE = .25
+
+-- arrival jitter; a tick inside this band confirms the sweep rather than
+-- re-anchoring it, or the spark hitches at every wrap
+local TICK_JITTER = .08
+
+-- Player::RegenerateAll:
+--   mod = GetTotalAuraModifier(SPELL_AURA_MOD_ENERGY_REGEN_TIME)
+--   if mod > 0 then mod = mod * agility / 10 end
+--   m_regenTimer += max(1, REGEN_TIME_FULL - mod)          -- milliseconds
+local REGEN_TIME_FULL = 2
+local ENERGY_REGEN_TIME_AURA = 217 -- SPELL_AURA_MOD_ENERGY_REGEN_TIME
+
+-- fixed magnitude is basePoints + baseDice (stored 11 -> 12); a die above 1 is
+-- a roll the client can't know, so it counts as nothing rather than a guess
+local amountCache = {}
+local function auraAmount(spellID)
+  local amount = amountCache[spellID]
+  if amount then return amount end
+  amount = 0
+  local effects = C_Spell.GetSpellEffectInfo(spellID) -- nil for an id with no record
+  if effects then
+    for i = 1, 3 do
+      local fx = effects[i]
+      if fx.auraName == ENERGY_REGEN_TIME_AURA and fx.dieSides <= 1 then
+        amount = fx.basePoints + fx.baseDice
+        break
+      end
     end
   end
+  amountCache[spellID] = amount
+  return amount
+end
 
-  return adjustedEnergyTick
+-- A passive is in effect exactly while known (current rank only, never in the
+-- buff list); anything castable or cast on us counts only while it is up.
+local function getEnergyRegenTimeMod()
+  local sum = 0
+  for _, spellID in ipairs(C_SpellBook.GetPlayerSpellsByAura(ENERGY_REGEN_TIME_AURA)) do
+    if C_Spell.IsSpellPassive(spellID) then
+      sum = sum + auraAmount(spellID)
+    end
+  end
+  for i = 1, 32 do
+    local spellID = select(10, C_UnitAuras.UnitAura("player", i, "HELPFUL"))
+    if not spellID then break end
+    sum = sum + auraAmount(spellID)
+  end
+  return sum
+end
+
+-- cleared on SPELLS_CHANGED (passives) and PLAYER_AURAS_CHANGED (buffs), and
+-- recomputed by the next tick that asks. Agility stays live: it's one call.
+local energyRegenTimeMod
+
+local function getAdjustedTickTimer()
+  if not energyRegenTimeMod then
+    energyRegenTimeMod = getEnergyRegenTimeMod()
+  end
+  if energyRegenTimeMod == 0 then return REGEN_TIME_FULL end
+
+  -- ms on the server, seconds here; the 1ms floor is the server's and this is a divisor
+  local reduction = energyRegenTimeMod * UnitStat("player", 2) / 10000
+  return math.max(0.001, REGEN_TIME_FULL - reduction)
 end
 
 pfUI:RegisterModule("energytick", function()
@@ -22,14 +84,53 @@ pfUI:RegisterModule("energytick", function()
     return
   end
 
+  -- inside the module body on purpose: C is on pfUI.env, not _G
+  local function getBarWidth()
+    return C.unitframes.player.pwidth ~= "-1" and C.unitframes.player.pwidth or C.unitframes.player.width
+  end
+
+  -- was this gain the regen tick? if so, re-anchor the sweep on it
+  local function lockTick(frame)
+    local now, period = GetTime(), getAdjustedTickTimer()
+
+    if frame.start then
+      -- signed distance to the nearest predicted boundary
+      local err = mod(now - frame.start, period)
+      if err > period / 2 then err = err - period end
+
+      if math.abs(err) <= TICK_TOLERANCE then
+        -- correct only what lies beyond normal jitter
+        if err > TICK_JITTER then
+          frame.start = frame.start + (err - TICK_JITTER)
+        elseif err < -TICK_JITTER then
+          frame.start = frame.start + (err + TICK_JITTER)
+        end
+        frame.max, frame.rejected = period, nil
+        return true
+      end
+
+      -- two rejected gains one period apart are the real clock: relock to it
+      local periodic = frame.rejected and math.abs(now - frame.rejected - period) <= TICK_TOLERANCE
+      if not periodic then
+        frame.rejected = now
+        return false
+      end
+    end
+
+    frame.start, frame.max, frame.rejected = now, period, nil
+    return true
+  end
+
   local energytick = CreateFrame("Frame", nil, pfUI.uf.player.power.bar)
   energytick:SetAllPoints(pfUI.uf.player.power.bar)
   energytick:RegisterEvent("PLAYER_ENTERING_WORLD")
   energytick:RegisterUnitEvent("UNIT_DISPLAYPOWER", "player")
   energytick:RegisterUnitEvent("UNIT_ENERGY", "player")
   energytick:RegisterUnitEvent("UNIT_MANA", "player")
-  energytick:RegisterEvent("CHAT_MSG_SPELL_SELF_BUFF")
-  energytick:RegisterEvent("CHAT_MSG_SPELL_PERIODIC_SELF_BUFFS")
+  energytick:RegisterUnitEvent("UNIT_SPELLCAST_SUCCEEDED", "player")
+  energytick:RegisterUnitEvent("UNIT_SPELLCAST_CHANNEL_STOP", "player")
+  energytick:RegisterEvent("SPELLS_CHANGED")
+  energytick:RegisterEvent("PLAYER_AURAS_CHANGED")
 
   energytick:SetScript("OnEvent", function()
     if UnitPowerType("player") == Enum.PowerType.Mana and C.unitframes.player.manatick == "1" then
@@ -42,44 +143,52 @@ pfUI:RegisterModule("energytick", function()
       this:Hide()
     end
 
-    -- Filter nur eigene Energy-Gewinne von Talents/Buffs
-    if event == "CHAT_MSG_SPELL_SELF_BUFF" or event == "CHAT_MSG_SPELL_PERIODIC_SELF_BUFFS" then
-      if string.find(arg1, "You gain") and string.find(arg1, "Energy from") then
-        this.ignoreNextGain = true
-      end
+    if event == "SPELLS_CHANGED" or event == "PLAYER_AURAS_CHANGED" then
+      energyRegenTimeMod = nil
       return
     end
 
     if event == "PLAYER_ENTERING_WORLD" then
-      this.lastMana = UnitPower("player")
+      this.lastPower = UnitPower("player")
+    end
+
+    -- the rule arms on the cast (Spell::TakePower: mana powerType, cost > 0),
+    -- not on a mana drop -- Mana Burn lowers mana without arming it
+    if event == "UNIT_SPELLCAST_SUCCEEDED" and arg1 == "player" then
+      local cost = C_Spell.GetSpellPowerCost(arg3)
+      cost = cost and cost[1]
+      if cost and cost.type == Enum.PowerType.Mana and cost.cost > 0 then
+        this.fsrSpell, this.fsrEnd = arg3, GetTime() + FIVE_SECOND_RULE
+        this.fsrGain = nil
+      end
+      return
+    end
+
+    -- Unit::Update won't expire the rule while the spending spell still channels
+    if event == "UNIT_SPELLCAST_CHANNEL_STOP" and arg1 == "player" then
+      if this.fsrSpell and this.fsrSpell == arg3 then
+        this.fsrEnd, this.fsrGain = GetTime() + FIVE_SECOND_RULE, nil
+      end
+      return
     end
 
     if (event == "UNIT_MANA" or event == "UNIT_ENERGY") and arg1 == "player" then
-      this.currentMana = UnitPower("player")
-      local diff = 0
-      if this.lastMana then
-        diff = this.currentMana - this.lastMana
+      local power = UnitPower("player")
+      local diff = this.lastPower and (power - this.lastPower) or 0
+      this.lastPower = power
+
+      -- only a gain can be the tick; a spend never touches the phase
+      if diff > 0 and lockTick(this) then
+        -- a tick inside the window proves regen continues through it
+        if this.fsrEnd and this.fsrEnd > GetTime() then
+          this.fsrGain = true
+        end
       end
 
-      if this.mode == "MANA" and diff < 0 then
-        this.target = 5
-      elseif this.mode == "MANA" and diff > 0 then
-        if UnitPower("player") >= UnitPowerMax("player") then
-          this.start = nil
-          this.spark:SetAlpha(0)
-          this:Hide()
-        elseif this.max ~= 5 and diff > (this.badtick and this.badtick * 1.2 or 5) then
-          this.target = 2
-        else
-          this.badtick = diff
-        end
-      elseif this.mode == "ENERGY" and diff >= 0 then
-        if not this.ignoreNextGain then
-          this.target = getAdjustedTickTimer()
-        end
-        this.ignoreNextGain = false
+      -- phase is kept while hidden; OnUpdate catches up by whole periods
+      if this.mode == "MANA" and power >= UnitPowerMax("player") then
+        this:Hide()
       end
-      this.lastMana = this.currentMana
     end
   end)
 
@@ -90,37 +199,53 @@ pfUI:RegisterModule("energytick", function()
     end
     this.tick = GetTime() + 0.020  -- ~50 FPS
 
-    if this.target then
-      this.start, this.max = GetTime(), this.target
-      this.target = nil
-      this.spark:SetAlpha(1)
-      this:Show()
+    -- five-second rule drains to nothing
+    local remaining = this.fsrEnd and (this.fsrEnd - GetTime()) or 0
+    if this.mode == "MANA" and remaining > 0 then
+      this.fsrbar:SetWidth(getBarWidth() * remaining / FIVE_SECOND_RULE)
+      this.fsrbar:Show()
+    else
+      this.fsrSpell, this.fsrEnd, this.fsrGain = nil, nil, nil
+      this.fsrbar:Hide()
     end
 
     if not this.start then
+      this.spark:SetAlpha(0)
+      return
+    end
+
+    if this.mode == "MANA" and UnitPower("player") >= UnitPowerMax("player") then
+      this.spark:SetAlpha(0)
       return
     end
 
     this.current = GetTime() - this.start
 
+    -- roll over by whole periods, not from now: restarting bakes frame
+    -- overshoot into the phase as drift the lock then has to chase
     if this.current > this.max then
-      -- Don't restart tick timer if mana is full
-      if this.mode == "MANA" and UnitPower("player") >= UnitPowerMax("player") then
-        this.start = nil
-        this.spark:SetAlpha(0)
-        return
-      end
-      this.start, this.max, this.current = GetTime(), getAdjustedTickTimer(), 0
+      this.start = this.start + this.max * math.floor(this.current / this.max)
+      this.max = getAdjustedTickTimer()
+      this.current = GetTime() - this.start
     end
 
-    local pos = (C.unitframes.player.pwidth ~= "-1" and C.unitframes.player.pwidth or C.unitframes.player.width)
-        * (this.current / this.max)
+    -- dim while the rule is up and nothing has ticked inside it yet
+    this.spark:SetAlpha((remaining > 0 and not this.fsrGain) and .4 or 1)
+
     if not C.unitframes.player.pheight then
       return
     end
+
+    local pos = getBarWidth() * (this.current / this.max)
     this.spark:SetPoint("LEFT", pos - ((C.unitframes.player.pheight + 5) / 2), 0)
   end)
 
+  energytick.fsrbar = energytick:CreateTexture(nil, "ARTWORK")
+  energytick.fsrbar:SetTexture(1, 1, 1, .15)
+  energytick.fsrbar:SetPoint("TOPLEFT", 0, 0)
+  energytick.fsrbar:SetPoint("BOTTOMLEFT", 0, 0)
+  energytick.fsrbar:Hide()
+
   energytick.spark = energytick:CreateTexture(nil, "OVERLAY")
   energytick.spark:SetTexture("Interface\\CastingBar\\UI-CastingBar-Spark")
   energytick.spark:SetHeight(C.unitframes.player.pheight + 15)
@@ -133,4 +258,4 @@ pfUI:RegisterModule("energytick", function()
     energytick.spark:SetWidth(C.unitframes.player.pheight + 5)
     hookUpdateConfig(pfUI.uf.player)
   end
-end)
\ No newline at end of file
+end)