Here's the information of skills of all Heroines and maximum possible attributes upgrade with Red Souls(100~3000), so you can have ideas to decide which Heroine you want to boost/place in the dungeon as a defender. (Note: Extra stat boost by Red Souls 100~3000 won't affect Raid power/awards when you put a Heroine to raid team.)

Reina 3000 [HP:940 ATK:71 DEF:71]
Normal Attack{Deals physical damage to one enemy unit.}
Area Protection{Raises the DEF of all allies in the same room for 7 seconds by 20 points.}
Embrace of Chaos{Raises the DEF of all allies in the entire dungeon for 15 seconds by 10 points.}
Blessing of Chaos{Raises the ATK of all allies in the entire dungeon for 15 seconds by 10 points.}
Salvation of Chaos{Heals 25% HP after receiving a fatal blow and teleports all enemy in the same room toe the spawn point.}

Note: You can leave Reina 3000 alone and will no longer need to worry about the Conceal units, because most of them will gonna commit suicide when they fight against Reina 3000(You may still need to use your magic skills properly). Remember to put Lv. 5 Jessica at the room in front of Reina's room so Reina may get extra buffs/healing from Jessica.

Claire 3000 [HP:460 ATK:92 DEF:92]
Normal Attack{Deals physical damage to one enemy unit.}
First Aid{Recovers one's own HP.}
Beginner's luck{10% chance of normal attacks and skill attacks dealing 100% more damage.}
Dual Strike{Deals physical damage twice to one enemy unit.}
Learning{Randomly activates an attack skill of an ally unit in the same room.}

Important Note: Claire 3000 is very ideal to put at the entrance room to take out most enemies, and she can use First Aid to heal herself. With this, the difficulty of this game will be substantially decreased.

Mavis 3000 [HP:650 ATK:64 DEF:111]
Normal Attack{Deals physical damage to one enemy unit.}
Dual Strike{Deals physical damage twice to one enemy unit.}
Braveheart{Increases one's own DEF in proportion to one's remaining HP.}
Resist Physical{Reduces physical damage taken by 30%.}
Cyclone{Deals physical damage to all enemy units in the same room.}

Jessica 3000 [HP:470 ATK:95 DEF:96]
Normal Attack{Deals physical damage to one enemy unit.}
Area Heal{Recovers the HP of all ally units in the same room.}
Area Protection{Raises the DEF of all allies in the same room for 7 seconds by 20 points.}
Area Force{Raises the ATK of all allies in the same room for 7 seconds by 20 points.}
Expand AoE{50% chance of afflicting the effects of an AoE skill with units in nearby rooms.}

Note: The Expand AoE passive skill may also expand Area Heal to nearby rooms.

Lynn 3000 [HP:410 ATK:160 DEF:60]
Normal Attack{Deals magic damage to one enemy unit.}
Spark{Deals magic damage to one enemy unit with a 40% chance of making the target dizzy.}
Cold Snap{Deals magic damage to one enemy unit with a 40% chance for slowing the target.}
Firestorm{Deals physical damage to all enemy units in the same room.}
Blizzard{Deals magic damage to all enemy units in the same room with a 40% chance of slowing the target.}

Important Note: You may be able to defeat a very strong enemy unit quickly with Lynn 3000. When a strong enemy unit starts fighting against Lynn 3000, use Terror Voice(Hot Key: V) to immobilize the strong enemy unit so the enemy unit will stand and unable to perform any attack for a short period, Lynn 3000 will take huge amount of HP off from the enemy unit with this.
https://youtu.be/A4c7ludB-o0
https://youtu.be/7MbrUS7witU
(You'll need to log in YouTube to see the videos.)

Melven 3000 [HP:500 ATK:105 DEF:105]
Normal Attack{Deals physical damage to one enemy unit.}
Dual Strike{Deals physical damage twice to one enemy unit.}
Resist Magic{Reduces magic damage taken by 30%.}
Reveal{75% chance of removing the Conceal status of all concealed enemy units inside a room.}
Area Charm{Charms all enemy units in the same room with a 50% chance.}

Mizuho 3000 [HP:630 ATK:78 DEF:108]
Normal Attack{Deals physical damage to one enemy unit.}
Flash Blade{Deals physical damage to one enemy unit and lowers their defense.}
Adversity{Increases one's own ATK in proportion to one's remaining HP.}
Clear and Serene{Gives 60% chance of enduring a fatal blow with 1 HP left.}
Dazzling Flourish{Deals physical damage to all enemy units and lowers their defense.}

Asuka 3000 [HP:490 ATK:120 DEF:97]
Normal Attack{Deals physical damage to one enemy unit.}
Mind's Eye{75% chance of removing the Conceal status of all concealed enemy units inside a room.}
Wide Whirlwind{Speeds up all ally units in the same room.}
Cicada Shell{25% chance of evading an enemy unit's attack.}
Headhunt{3% chance of insta-killing an enemy unit you deal damage to. (Ineffective against Heroines.)}

Henrietta 3000 [HP:630 ATK:125 DEF:125]
Normal Attack{Deals physical damage to one enemy unit.}
Aura of Protection{Increases the DEF of all ally units in the same room at a fixed interval for 12 seconds, up 15 points.}
Aura of Judgment{Deals magic damage to all enemy units in the same room at fixed intervals.}
Aura of Debility{Decreases the ATK of all enemy units in the same room at a fixed interval for 12 seconds, down 15 points.}
Aura of Anguish{Afflicts all enemy units in the same room with Poison, Slow, Forget, or Dizzy at fixed intervals.}

Note: I'd never tried to put Mizuho, Asuka, and Henrietta on the field once yet because they're all put in the raid team by me.