SELECT MobInfo.Name, MobInfo.Level as MLevel, MobInfo.ID, WeaponTitleData.LLevel, WeaponTitleData.Suffix
FROM MobInfo
JOIN( SELECT MobID, MAX(Level) as LLevel, Suffix FROM WeaponTitleData GROUP BY MobID) AS WeaponTitleData ON MobInfo.ID = WeaponTitleData.MobID;

This seems to work, almost.

In my join, I need to get suffix where WeaponTitleData.Level = LLevel, but can't figure out how to do it...