Even though Yumi and Alucard don't fully trust Jin, what he told them makes a lot of sense. Their water bottles are already empty, and they have no choice but to go down the giant tree they're hanging from.
Yumi was also worried because Jin said his plan would put Alucard in danger.
Alucard sighed and looked at Jin. "I don't like the idea of being in danger, but tell us your plan, and then I'll decide."
"Alright, but it would be best if I knew about your abilities and weaknesses since I know very little about you both. Maybe one of you has an ability that could help with the plan."
"Why should we tell you our abilities and weaknesses? Who knows, you might use this information against us!" Yumi responded sharply.
"I'll reveal my abilities and weaknesses too, so you don't have to worry about that," Jin replied.
"Hmph, why should I care about that?" Yumi said.