The fact that Luna was the only one with enough flux energy to spare was both good and bad for the group. Good, because she was able to maintain the summon of Babieca for a long period of time and bad because as much as they would have loved to hunt something along the way, Luna wasn't powerful enough to reassure Uriel of an easy victory.
Had they stumbled upon a beast level cryptid, Uriel might have gained enough flux energy to go on hunting on his own to recharge the battery of his smartphone, but each POI they saw seemed ominous and ancient, both good indicators of a powerful cryptid inside.