You seem to be facing a delimma. Here's how I would go about solving it:
If a writer is inactive, their characters can be considered off-limits within the clan's official continuity until they return to say otherwise. If the active writer(s) wish(es) to tell a story within the clan's continuity, which is to say use characters belonging to other writers who are a part of the clan, they may do so if they acknowledge that the story being written may not be considered official to the clan following the return of the inactive user(s).
Ex: I (member of "Example Clan") write a story where my character, Dante, kills my clan member's character. Aforementioned clan member returns the next day, and asserts that their character was in fact not killed. It would be within the power of "Example Clan", at the request of (or arguably even on behalf of) the clanmate whose character was killed by Dante Rockwell, to completely disregard the story in which my character Dante Rockwell kills his clanmate, and keep my clanmate's characters alive for the next monthly/weekly/collab/event for the purposes of official "Example Clan" continuity.
I keep putting the word 'official' in italics. I'm stressing that particular word because, technically, you could write a story with your character, which you each have ownership of, in which every other character in the clan is permanently altered. But whether or not that story is a part of the 'official' clan continuity is up to whoever is 'officially' in charge of the clan.
But you're all writers here. Do as you please, and don't let anyone tell you what you can and can't write other than who you say gets to tell you what you can and can't write. And even then, their word ain't law, they just get to call you out for breaking your word without lying.
Cheering from the sidelines!
~Chrome
