I'm using interlude as well. This is not the skill XML. Now go back to gameserver\data and open armor_sets.xml
then ctrl+f and find ID 7868 and tell look the skills="HERE IS THE ID", after that go to gameserver\data\stats\skills and find the skill and paste it here.
<set id="49" chest="7867" head="7860" gloves="7868" feet="7869" skills="3610-1" enchant6skills="3622-1" />
<skill id="3610" levels="1" name="Apella Robe Set">
<!--
Description:
Maximum CP +177 and +40% CP recovery speed. When under attack from an opposing PC, debuff can be cast at an 80% success rate.
When all set items are enchanted by 6 or higher, P. Def. and Weight Gauge will increase.
-->
<set name="icon" val="icon.armor_t1006_ul_i00"/>
<set name="magicLevel" val="1"/>
<set name="target" val="TARGET_SELF"/>
<set name="skillType" val="BUFF"/>
<set name="operateType" val="OP_PASSIVE"/>
<triggers>
<trigger id="5024" level="6" type="RECEIVE_DAMAGE" chance="80">
<player damage="50;0" />
</trigger>
</triggers>
<for>
<mul order="0x30" stat="expLost" val="0.8">
<target pvp="true"/>
</mul>
<add order="0x40" stat="maxCp" val="177"/>
<mul order="0x30" stat="regCp" val="1.40"/>
</for>
</skill>