Like many Vampires, Meline Leopold had an affinity with the Dark Element and had long dedicated her spellcraft to stealth. It worked especially best at nighttime or in dark areas— Dark areas such as the underground hideout they all just so fortunately happened to be in. There were mana lamps to provide light but more than enough dark areas to exploit.
Still, she was not confident in a quick stealth spell. She needed preparation. She needed help which the others—Nadine, Hayden, and Hugo Leopold—provided by supplying Mana quietly and secretly to the spell she prepared.
As stated earlier, the fact that Caius and the Leopolds arrived here after Alexia was due to fairly detailed planning. Caius didn't have the strength to confront Brogan directly so his role was mostly to be there to protect them from Brogan's noble authority. As such, he was going to need to rely on the strengths of those he was bringing along.
