Between the number of times you do or don't trigger prowess by slinging spells around, seekers on average going to be worth 3/6 more points of damage from triggers and being able to attack through coursers. On the flip side, assuming neither gets killed for a couple turns, grandmaster's gaining you a lot more life while actually doing things in postboard games.Is it better than Seeker though? I'd imagine you'd want at least 12 burn spells to make Soulfire better.Back to standard, I think soulfire grandmaster will have more impact then monastery mentor in jeskai builds. The lifelink on your burn spells is phenomenal and when I was playing with mentor, I found I was having trouble convoking stokes without rabble tokens around.
Agreed on Mentor though. I feel like Rabblemaster is better in most cases, and Brimaz too for that matter.
Against most midrange decks, you often just board out seeker because it's worth about 4 damage on a good day, then is a blank in your deck outside of chump blocking, while grandmaster is actually a threat going long and adds value to all your burn spells which would otherwise be mediocre removal. You're also a lot more resilient to the multiple rhino draw.
