In ...\Steam\steamapps\workshop\content\289070\945917617\Mikasa_config.xml
Copy this entire row:
<Row>
<Domain>StandardPlayers</Domain>
<CivilizationType>CIVILIZATION_GAKUINTOSHI</CivilizationType>
<LeaderType>LEADER_MIKASA</LeaderType>
<CivilizationName>LOC_CIVILIZATION_GAKUINTOSHI_NAME</CivilizationName>
<CivilizationIcon>ICON_CIVILIZATION_GAKUINTOSHI</CivilizationIcon>
<LeaderName>LOC_LEADER_MIKASA_NAME</LeaderName>
<LeaderIcon>ICON_LEADER_MIKASA</LeaderIcon>
<CivilizationAbilityName>LOC_TRAIT_CIVILIZATION_GAKUINTOSHI_CHONOURYOKU_KAIHATSU_NAME</CivilizationAbilityName>
<CivilizationAbilityDescription>LOC_TRAIT_CIVILIZATION_GAKUINTOSHI_CHONOURYOKU_KAIHATSU_DESCRIPTION</CivilizationAbilityDescription>
<CivilizationAbilityIcon>ICON_CIVILIZATION_GAKUINTOSHI</CivilizationAbilityIcon>
<LeaderAbilityName>LOC_TRAIT_LEADER_MIKASA_RANGE_NAME</LeaderAbilityName>
<LeaderAbilityDescription>LOC_TRAIT_LEADER_MIKASA_RANGE_DESCRIPTION</LeaderAbilityDescription>
<LeaderAbilityIcon>ICON_LEADER_MIKASA</LeaderAbilityIcon>
<Portrait>LEADER_MIKASA_NEUTRAL</Portrait>
</Row>

And paste it just below, then change <Domain>StandardPlayers</Domain> into
<Domain>Players:Expansion1_Players</Domain>

Then in ...\Steam\steamapps\workshop\content\289070\945917617\MikasaMikoto.modinfo
Copy
<Criteriaid="LeaderCriteria">
<LeaderPlayable>StandardPlayers::LEADER_MIKASA</LeaderPlayable>
</Criteria>
and also paste it just below, then change the above one
<Criteriaid="LeaderCriteria">
<LeaderPlayable>StandardPlayers::LEADER_MIKASA</LeaderPlayable>
</Criteria>
into
<Criteriaid="LeaderCriteria"><LeaderPlayable>Players:StandardPlayers::LEADER_MIKASA,StandardPlayers::LEADER_MIKASA,Players:Expansion1_Players::LEADER_MIKASA</LeaderPlayable>
</Criteria>
and the below one into
<Criteria id="LeaderCriteria_Expansion1">
<LeaderPlayable>Players:Expansion1_Players::LEADER_MIKASA</LeaderPlayable>
</Criteria>
Finally in ...\Steam\steamapps\workshop\content\289070\945917617\Mikasa_Leaders.xml
Change the <leader> row into
<Row LeaderType="LEADER_MIKASA" Name="LOC_LEADER_MIKASA_NAME" Sex="Female" InheritFrom="LEADER_DEFAULT" SceneLayers="2"/>

在相應的檔案內複製貼上斜體字，然後把劃線部分改為粗體部分就可以了。應該