{felidar sovereign} does his 40+ life triggered ability take effect in EDH where life totals are doubled?
Yes it does. However, it is open to debate within your playgroup.
Or would it be 80 life like poison counters are doubled
In theory you win as soon as you play it, but most EDH groups say it ability triggers at 80 life, otherwise it's not fair
Poison counters are not doubled; it still takes 10 to kill a player. Same thing with the sovereign, once you hit 40 life, you win at your next upkeep. As long as it still lives, of course.
And here's the official ruling:
903.12. The EDH variant includes the following specification for winning and losing the game. All other rules for winning and losing the game also apply.
903.12a A player thats been dealt 21 or more combat damage by the same general over the course of the game loses the game.
RESOLVED
Thanks guys