Curse effect (Ghastly Dragon)

[Exura ATS]

Hey guys!

How I can add a curse effect to attacks from ghastly dragon like character gets "poisoned" by giant spiders on physical attack?

*P.S.: I don't use "curse" spell on spells.lua, because I have changed vocation mechanics.

Ghastly Dragon.xml:

<?xml version="1.0" encoding="UTF-8"?>
<monster name="Ghastly Dragon" nameDescription="a ghastly dragon" race="undead" experience="4600" speed="410" manacost="0">
<health now="7800" max="7800"/>
<look type="351" corpse="11362"/>
<targetchange interval="5000" chance="8"/>
<strategy attack="100" defense="0"/>
<flags>
<flag summonable="0"/>
<flag attackable="1"/>
<flag hostile="1"/>
<flag illusionable="1"/>
<flag convinceable="0"/>
<flag pushable="0"/>
<flag canpushitems="1"/>
<flag canpushcreatures="1"/>
<flag targetdistance="1"/>
<flag staticattack="90"/>
<flag runonhealth="366"/>
</flags>
<attacks>
<attack name="melee" interval="2000" skill="92" attack="100" poison="1200"/>
<attack name="poisoncondition" interval="2000" chance="8" target="1" range="7" min="-920" max="-1280">
<attribute key="shootEffect" value="poison"/>
<attribute key="areaEffect" value="poison"/>
</attack>
<attack name="lifedrain" interval="2000" chance="15" range="7" target="1" min="-80" max="-230">
<attribute key="areaEffect" value="redshimmer"/>
</attack>
<attack name="physical" interval="2000" chance="9" range="7" target="1" min="-2" max="-1377">
<attribute key="shootEffect" value="suddendeath"/>
<attribute key="areaEffect" value="mortarea"/>
</attack>
<attack name="physical" interval="2000" chance="11" radius="4" min="-0" max="-180">
<attribute key="shootEffect" value="suddendeath"/>
<attribute key="areaEffect" value="mortarea"/>
</attack>
</attacks>
<defenses armor="45" defense="35">
<defense name="speed" interval="2000" chance="10" speedchange="550" duration="5000">
<attribute key="areaEffect" value="redshimmer"/>
</defense>
</defenses>
<elements>
<element firePercent="10"/>
<element icePercent="50"/>
<element physicalPercent="-10"/>
<element holyPercent="-15"/>
<element energyPercent="-10"/>
</elements>
<immunities>
<immunity paralyze="1"/>
<immunity invisible="1"/>
<immunity death="1"/>
<immunity earth="1"/>
</immunities>
<voices interval="5000" chance="10">
<voice sentence="EMBRACE MY GIFTS!" yell="1"/>
<voice sentence="I WILL FEAST ON YOUR SOUL!" yell="1"/>
</voices>
<loot>
<item id="11366" chance="6950" /><!-- ghastly dragon head -->
<item id="8473" chance="5525" /><!-- ultimate health potion -->
<item id="11368" chance="1125" /><!-- jade hat -->
<item id="5944" chance="12650" /><!-- soul orb -->
<item id="11323" chance="8525" /><!-- zaoan halberd -->
<item id="8472" chance="4150" /><!-- great spirit potion -->
<item id="2152" countmax="2" chance="23300" /><!-- platinum coin -->
<item id="11301" chance="1225" /><!-- zaoan armor -->
<item id="7591" chance="10700" /><!-- great health potion -->
<item id="11367" chance="21375" /><!-- undead heart -->
<item id="2148" countmax="100" chance="43725" /><!-- gold coin -->
<item id="2148" countmax="100" chance="43725" /><!-- gold coin -->
<item id="2148" countmax="68" chance="43725" /><!-- gold coin -->
<item id="6500" countmax="3" chance="9600" /><!-- demonic essence -->
<item id="9810" chance="3500" /><!-- rusty armor -->
<item id="11304" chance="1650" /><!-- zaoan legs -->
<item id="11309" chance="5775" /><!-- twin hooks -->
<item id="11305" chance="1075" /><!-- drakinata -->
<item id="11355" chance="1200" /><!-- spellweaver's robe -->
<item id="11227" chance="1325" /><!-- shiny stone -->
<item id="11240" chance="650" /><!-- guardian boots -->
<item id="11307" chance="550" /><!-- zaoan sword -->
<item id="11303" chance="1550" /><!-- zaoan shoes -->
<item id="11302" chance="650" /><!-- zaoan helmet -->
</loot>
</monster>