You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alllinks galcontinue="Deck:紫白_全体除去ビート" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="BLACK&amp;BLUE" missing="" />
      <page ns="0" title="BLADE" missing="" />
      <page ns="0" title="Danciao" missing="" />
      <page pageid="263" ns="0" title="CA" />
      <page pageid="247" ns="0" title="CAヤード" />
      <page pageid="254" ns="0" title="CB" />
      <page pageid="550" ns="0" title="Deak:ナイトクドゥラク" />
      <page pageid="317" ns="0" title="Deck:オーラでブレイク" />
      <page pageid="258" ns="0" title="Deck:ヒャッハー!〇〇は消毒だー！" />
      <page pageid="260" ns="0" title="Deck:暗黒の領主時代ラッシュ" />
    </pages>
  </query>
</api>