I might give a lot of weight to instant-speed trample effects, but I've won too many games with them to underrate this activated ability
Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Legal Toolbox Buy This Card Notes and Rules Information for Aragorn, Company Leader: If the creature you choose as your Ring-bearer was already your Ring-bearer, that still counts as choosing that creature as your Ring-bearer for the purpose of abilities that trigger "whenever you choose a creature as your Ring-bearer" or abilities that care about which creature was chosen as your Ring-bearer
If your three drop is Lightning Helix plus cantrip then everything works out
Of course, four mana is a much steeper investment than Brainstorms single-mana cost, so Jace really only pays off in the long run
If the target permanent is made up of multiple cards (due to mutate or meld, for example), that permanent's controller puts all of them on the top or all of them on the bottom
Even if youve only used Evolving Wilds and Harrow by the time you cast it, four mana for two lands is still pretty reasonable