If instants or abilities change the powers of these creatures, the mentor trigger may or may not resolve depending on its power at the time of the second check
Testuj gry w trybie demo, zanim zagrasz na prawdziwe rodki
Like most Magic: The Gathering cards, the value of Brago's Favor depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Conspiracy)
I won more than one old Vintage tournament that way with nothing in my deck more expensive than Jester's Cap, thanks to turn after turn of card advantage
1 Elspeth Resplendent Planeswalkers that protect themselves are almost always better than those that can't defend their valuable loyalty counters, and Elspeth Resplendent is no different in this regard
All told I think I prefer this for most applications