Just to clarify, if you have multiple Triskel cards with the timing, "after you played a season card," you can play all of them on the same turn? I would have thought that once you played a Triskel card, the next card wouldn't be a valid move because you were no longer playing it after a season card you were playing it after a Triskel card. But that is incorrect?
I believe if you laid down both Triskel cards at the same time it would work. Thus you are playing both cards directly after the season's card. This would explain how some players play the same timing effect triskel card.