No, Sacrificing a creature is a cost of Eldritch Evolution. You pay costs as the last step of casting a spell and putting the spell on the stack is the first step to casting a spell. This means that Eldritch Evolution is already on the stack when Seedguide Ash dies and the trigger goes on the stack above Eldritch Evolution and will resolve first.
September 13, 2017 12:59 a.m.
September 16, 2017 12:07 p.m.
Let's say i have Bosk Banneret on the field.3th round i play Eldritch Evolution and sacrifice Bosk Banneret so i search for Iwamori of the Open Fist in my library and play a Legendary card like Omnath, Locus of Rage from my hand
September 16, 2017 12:12 p.m.
Iwamori of the Open Fist will trigger as it enters the battlefield, regardless of how it entered. However, Iwamori of the Open Fist only allows opponents to play a legendary creature. If you control Iwamori's ability, you will not be able to play Omanth from your hand.