4 points
This ability was designed for high level play. I would have tweaked it to deal 4d6 or 3d8, or just handwaved the massive damage rule.
18 points
Since that’s a L17 player ability, I’m betting the point is that reducing to 0hp is generally more damage than (55) 10d10. So as a DM I’d rule it that it still takes you to 0 and doesn’t do massive damage (instant kill)
4 points
They’re introducing the BBEG to a level 1 party, so that barbarian probably only has around 10 hp
3 points
Don’t classes start at max HP? So he has atleast 12, plus whatever con modifier he got going.
2 points
The specific details aren’t important, but yeah. A lot less HP than can survive 10d10 damage.
