Altogether, I would say a scenario similar to the one suggested by [@The Harbinger of Ferocity] would succeed in gathering the party together quite plausibly - namely, Athera and [@Mistiel]'s Ceria happening upon each other I the course of their travels, then encountering mine and [@Turbowraith]'s characters, who, as I might have previously mentioned somewhere, had issued together from their shared region of origin, and banding together either for greater safety or against some better-defined common threat or obstacle. [@Ermine]'s warlock could have then joined the group at some settlement or other resting-place, possibly deeming such a group to have the potential to entangle itself in some memorable adventure or the other.