Cave of Trials-7
Enemy Name: The Fallen
Enemy Hero: Fallen Angel Lucifer
Enemy Level: 9,500
Hero Stats: 9,450,000 HP / 104,998 Att / 69,999 Def
Aptitude: 0 / 0 / 0
Boss Spells: Special Attac, Holy Judgment.
Super Shadow Goblin (EX)*
Enemy Items: Lucifer Spear, Infinity Blade, Armor of Darkness(x2), ??? Potion.
BP Cost: 4,000 BP.
Exp Reward: 60,000 Exp.
Item Reward: Rate Stone
Strategy: I recommend using Holy Angel Seraphiel and Mermaid+. You gotta spam mermaid+ and IB2 the fallen angels. Now your main problem is stopping the enemy hero from using holy judgement to wipe out all of your units.
There are 2 known methods of doing this.
Method 1: Before the enemy gets close to enough mana to use holy judgment, fly past the enemy hero to make it cast it's special attack instead. This may require you to have the enemy population down quite a bit below yours or the enemy will wait until it's blue bar is full to summon fallen angels then instantly have enough mana to cast holy judgement. This generally happens when your mermaids aren't strong enough to kill the enemy shadow goblins in 1 hit.
Method 2: If method 1 fails, you will need to turn the enemy hero around. To do this, you must make sure it doesn't have any units too far in front of it then get up then charge forward with your hero. It works even better if the enemy hero is a bit forward from it's starting spot.
Once you have a decent amount of mermiads out, it's just a matter of time before you win. You will need to keep spamming mermaids cause they will slowly die off even when you have 90 of them.
The lowest level that I've managed to do this is level 750 with 4 Dragon Steak Barbeques and 2 Faatality Drinks. There was absolutely no room for error. I would suggest being at least level 1500 to try to beat it.
If for some reason there's no way you can get Seraphiel at this point, you can still do it with with a powerful gold cost hero (such as Khronos) at a high level. (I got khronos at level 3500 but I'm pretty sure it can be done at a much lower level if you use lots of dragon steak bbqs) With a hero so much slower than sera, you need to use method 2 or you may get killed by special attack.
You need to kill all of the fallen angels with meteor 3 and walk forward until the enemy hero turns around. (I was using heal while spamming mermaids at this point so I could take more hits in case I would make a mistake.) When it casts holy judgement off screen, walk away until you are out of it's range. Walk forward again to make it turn around again. Just keep repeating the process until the enemy starts to change it's pattern and starts using special attack. By this time you should have enough mermiads built up and you can just keep spamming mermiads and rage.
If you can't seem to get the timing down for stopping (or redirecting) holy judgement, you have 2 choices: 1 Use ghato as your hero to make mermaids invincible or 2 use Aeon as your unit. Aeon is ranged and resists shock so at a high level he can actually survive multiple holy judgements.