Disruption Shield correctly explodes once your mana dips below 50%, for whatever reason

game/modules/tome/class/Actor.lua

@@ -5327,6 +5327,16 @@ function _M:paradoxDoAnomaly(chance, paradox, def)
 	end
 end
 
+-- Overwrite incParadox to set up threshold log messages
+local previous_incMana = _M.incMana
+function _M:incMana(mana)
+	if mana < 0 and self:isTalentActive(self.T_DISRUPTION_SHIELD) then
+		self:callTalent(self.T_DISRUPTION_SHIELD, "doLostMana", mana)
+	end
+
+	return previous_incMana(self, mana)
+end
+
 -- Overwrite incParadox to set up threshold log messages
 local previous_incParadox = _M.incParadox
 

game/modules/tome/data/talents/spells/arcane.lua

@@ -199,11 +199,19 @@ newTalent{
 		local max = t.getMaxAbsorb(self, t)
 		self.disruption_shield_power = math.min(self.disruption_shield_power + max / 10, max)
 	end,
+	doLostMana = function(self, t, mana)
+		if (self:getMana() - mana) / self:getMaxMana() < 0.5 then
+			self:forceUseTalent(self.T_DISRUPTION_SHIELD, {ignore_energy=true})
+		end
+	end,
 	callbackOnHit = function(self, t, cb, src, dt)
 		local p = self:isTalentActive(t.id)
 		if not p then return end
 		if cb.value <= 0 then return end
-		if self:getMana() / self:getMaxMana() < 0.5 then return end
+		if self:getMana() / self:getMaxMana() < 0.5 then
+			self:forceUseTalent(self.T_DISRUPTION_SHIELD, {ignore_energy=true})
+			return
+		end
 		-- if self:reactionToward(src) > 0 then return end
 		self.disruption_shield_power = self.disruption_shield_power or 0
 		self.disruption_shield_storage = self.disruption_shield_storage or 0