Hello all. Another guide, as always, hope it helps. I have finished this event mostly because I’ve wanted to write a guide about it since a lot of people struggles in this event. 
The rewards… I cant say they’re null but don’t expect more than 1 or 2 pulls and some emblems.
As my other guides, just like Contest of elements guide, this is how I made it. It does not means its the best strategy. I also don’t have expensive heroes so this will mostly help free or very cheap to play players. I do own 2 or 3 premium heroes but they were acquired by luck.
✔ Strategy:
》 Overheal is a must. Mobs and bosses will hurt even your past 5 generations with one hit. You’ll need enough health to survive that.
Overheal heroes I’ve used:
The pig is special since he does damage too. If you have his costume, consider yourself lucky. I don’t own it.
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》Counterattack was primordial to me. I don’t have enough firepower for killing these infinite health bosses. So… well… why not let them kill themselves?
Counterattack heroes I’ve used:
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》Damage. Some heroes are key, other are support but one thing is true: you’ll need to combo your best hero matches to deal damage. Mobs are hard to kill.
Most important damage heroes in my run:
Khagan will also help to load your heroes faster. His mana buff was amazing.
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》Healing is also a must. For doing an overheal, you need full health. So keeping my health always at max was very important. I’ve mostly used 2 healers: Ariel (from 100 coins in atlantis portal) and Lady of the Lake (Soul Exchange).
Lady’s minions mana control and Ariel’s mana buff did a superb job.
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》Blind: this category includes my secret super weapon: Motega. His butterflies kept my enemies forever blind + unable to heal. This is life saving. Even it means enemies going to miss some attacks and don’t get hurt by counterattack. It does not matter. Bosses damage is so high, so high that even if they hit only one hero, it’s enough.
His minions will let you deal +20% damage when you can’t use Franz. Also, minions = extra health.
Extra gameplay tips & items:
• For normal difficulty until half impossible, I have made as much damage using Guillin and Carol as possible. Their skills are reduced for 1 turn, so you can deal huge damage with them every turn.
• Kashhrek was more useful than I thought.
• Glenda + Mr. Pengui combo is deadly, but won’t be enough in later stages.
Items and blessings:
• mana potions only until half impossible.
• timestop, tornadoes and reflect shields can do wonder.
• all my blessings were chosen on mana speed.
For more something more visual and to let you know how I handle the boards, here is a video of me beating the last impossible stage:
》》》 Tower of Styx: stage impossible 25 (free to play) - YouTube
• Final stage items and team:
Hope it helps somehow!!!
Enjoy!
A hug from Rebel Forces alliance! 
Final score and loot:
