They're just talking about the dialogue they have in certain situations. In terms of importance you don't actually need any characters with you at all, but the things they say are neat sometimes.
Whatever you do though do not attempt to solo the game with Luka. Fucking imps.
/mggg/ - Monster Girl Games General #64
Zachary Richardson
Xavier Richardson
Yeah it took a long time before I got rid of Nuruko:
>great single-target damage with her triple attack and Full-Gatling
>great aoe with her other machina abilities
>tentacle caress for huge aoe pleasure damage
She's great to have for a long time. I didn't get rid of her until Hild, and I still occasionally miss her aoe pleasure, since it's really hard to find
Levi Allen
The L4D Hunters of Paradox.
Lincoln Bell
...
Bentley Edwards
Even if the imps don't get you because Luka can one-shot them, there'd still be Saki.
Dominic Moore
Saki-chan *twinkle*
Juan Nguyen
At least you don't need to fight her to beat the game.
Finding imps randomly and fuckinng up your run because you failed escaping/got hit with the bind is very frustrating.
At least you don't get punished for dying this game.
Blake Richardson
I love you, Voreanon
Parker Watson
I love you, Voreanon!
Evan Phillips
skunk girls