Because she gets the trigger at the end of the turn, rather than during your upkeep, she cannot be answered on other turns, or give folks a full round of answers
Let's try to quantify the impact these two cards have on the overall price of the format
Bloodspore Thrinax only has devour 1 and it will have each creature I control enter the battlefield with an additional X +1/+1 counters where X is the number of +1/+1 counters on Bloodspore Thrinax
The set is only 50 cards, so its going to be the easiest set review Ive ever done
A few months back, Raging River, aka Micah of the NY Sisters of the Flame, announced that hed created cards for an unreleased Magic set, and wanted to treat it like a normal WotC spoiler season
You can tap it and three mana and sacrifice another dork and then have an opponent lose life equal to its toughness, so that's another winning condition outside of the red zone when a foe has a low life