Encontrei a slução
SELECT
ch.charId,
ch.char_name,
ch.base_class,
c.pvpkills,
c.pkkills
FROM
character_kills AS c
JOIN characters AS ch ON c.charId = ch.charId
WHERE c.charId NOT IN (SELECT charId FROM heroes) AND
ch.base_class = '113'
ORDER BY
c.pvpkills DESC,
c.pkkills ASC