Some pointers to get S ranking in 'Normal Mode' Solo dungeon (to unlock hero):
* Take off troops and sylph as these can do damage that you're meant to be doing (therefore decreasing your damage dealt)
* Do all side caverns etc you can (you do need attempt for tombs, not others)
* If you face a mage or lizard (or any other monster that heals itself), do your 'support skills' to allow it to heal as much as you can
* If a monster/boss can 'summon' more monsters, let it do this as much as possible (without compromising damage dealt to yourself)
* If you are gaining daru from tombs (instead of fights), wait an hour or two and try again
* Try to 'Over kill'. That is, hit afk until monster is almost dead, then give all you have (if you have to). More damage you do, the better
Hope this clears some things up, and good luck
* Take off troops and sylph as these can do damage that you're meant to be doing (therefore decreasing your damage dealt)
* Do all side caverns etc you can (you do need attempt for tombs, not others)
* If you face a mage or lizard (or any other monster that heals itself), do your 'support skills' to allow it to heal as much as you can
* If a monster/boss can 'summon' more monsters, let it do this as much as possible (without compromising damage dealt to yourself)
* If you are gaining daru from tombs (instead of fights), wait an hour or two and try again
* Try to 'Over kill'. That is, hit afk until monster is almost dead, then give all you have (if you have to). More damage you do, the better
Hope this clears some things up, and good luck