Version 1.14.105 offers 18 new secrets characters:

1. Torino
   
2. Secretino Dagsson
   
3. Morris Baldwin
   
4. Hugh Baldwin
   
5. Persephone
   
6. Astarte
   
7. Tera
   
8. Annette
   
9. Genya Arikado
   
10. Jiangshi
    
11. Ruler Sword
    
12. Drolta Tzuentes
    
13. Atlantis Shrine Wizard
    
14. Witch Actrise
    
15. Zephyr
    
16. Stone Skull
    
17. Fake Trio
    
18. Slogra and Gaibon

Also there is another secret weapon called Chaos Rune.(Thanks to Costrictor. His reply under guide "Weapon Evolutions & Unions(1.14.105)" revealed to me that there's another secret weapon out there.)
https://steamproxy.com/sharedfiles/filedetails/?id=3596017317

This guide gives a brief overview of my experience unlocking each secret, but is not entirely sure exactly how it is triggered.

P.S. As of now, most other secrets have been conceptualized but remain unfinished.

中文版链接：
https://steamproxy.com/sharedfiles/filedetails/?id=3595447362

Witness the 17th Colossus wander to new horizons.



After unlocking the map Mazerella, move one space left, then proceed straight up until you see the Colossus. Once you attack it to activate it, do not attack it again. Follow it from a safe distance until it exits the bottom edge of the map.









Torino Character data as follows:

Spend your afterparty with the foolish high roller.



After unlock map Westwoods and Chula-Reh and Masquerade relic you can buy Preorder Me! in Gicare.



Secretino Dagsson character data as follows

Choose Nathan Graves and use Arch Angle(Grand Cross + Heaven Sword)

Use these weapons in one Dairy Plant run. (Victory Sword, Heaven Sword, Tyrfing, Icebrand, Sword Brothers, Confodere)

Send Simon on a windy quest beneath a gorgeous moon.



Use Simon Belmont evolve the Spirit Tornado Tip and Venus Crescent. Synthesis table as follows.









Persephone Character data as follows:

Practice non-violence amongst the flowers with the charmed young Morris.



Use Jonathan Morris and initial weapon selection any three weapons other than the Javelin. In map il Molise when selecting weapons at the start, choose to skip. Just AFK til 5:00 and quit. IT MUST BE 5:00. 5:01 OR 5:02 WON'T UNLOCK THIS SECRET.





Astarte character data as follows

Slay 10,000 Red foes that denyDeath.



Kill 10,000 Scarleton

Tera character data as follows

Build one tower inside another.



Evolve the Clock Tower in map Gallo Tower . Synthesis table as follows.





Annette Character data as follows:

Let Hakuba rebuke the lying Reaper to reveal her allies' truth.



Use Mina Hakuba kill The Trickster(Purple Reaper). For convenience, you may defeat them in the map BOSS RASH.





Genya Arikado Character data as follows:

Eat the souls of 10,000 Forest frogs.



Use Dark Frogamorphosis kill 10,000 enemies in Mad Forest (The enemies count only for Dark Frogamorphosis kill).







Jiangshi Character data as follows:

Spell the ruler's word.



Just spell rulersword in Cast Spell



Ruler Sword character data as follows

Witness the 7th rebirth of Dracula's niece on holy ground.



Select Character Elizabeth Bartley Select Arcanas “IV- Awake” and have level 2 Tirajisú to make sure 6 revivals(die 6 times) in Cappella Magna





Drolta Tzuentes character data as follows

Combine holy liquids in a sunken city.



Choose map Moongolow Evolve Hydro Storm to Hydro Pump Climax.The synthetic table as shown.





Atlantis Shrine Wizard Character data as follows:

Slay an elder crone with a riotous young witch where a stone mask sleeps.



Use Carrie Fernandez to kill Hug in reverse mode Inlaid Library.





Witch Actrise Character data as follows:

Use Soma Cruz after reaching the 30 minute Ode to Castlevania kill Zephyr

Slay an inverted skeletal sphere with the Vessel of Dominus.



Use Shanoa enter the mapThe Bone Zone in inverse mode, then kill Sketamari.





Stone Skull character data as follows

Defeat Death's demonic knight duo with Dracula's smallest henchman.



The game will automatically unlock after the update. However, the unlock method can be determined based on the original text. Location is shown in the figure. Use Fleaman to enter the map Ode to Castlevania, then kill Slogra & Gaibon.





Slogra and Gaibon character data as follows

You need casting the spell "guinigigi" in the Cast Spell. And its evolution Wicked Ruler is showed in as picture. You need to upgraded Spellbinder to Max level. Also after spell "guinigigi" you need to choose it when leveling up.