If they change once a week, then this week's one is a cake walk, although we did have Charlie with us and he could probably solo it. It's a wizard thing, when he spawns the ground stays on fire but there's one area which is fire free, by standing on it you get some or other buff which allows you to damage him, he's untouchable otherwise. Have someone stand in the fire-free area to zerg adds as there will be many of them. Other two simply get buff, nuke wizard, get buff, nuke wizard, etc etc. Took about 5 mins, really easy.
That mini crota was a dick, but I think it'll get easier over time as the community figures out how it works. It's basically crota: kill sword bearer ---> take sword ---> everyone else take his shields down so he kneels ---> whack with sword ----> start again.
Takes a shit ton of firepower though, so come prepared.