If you attack with multiple creatures equipped with Hexplate Wallbreakers in one combat phase (or one creature equipped with multiple Hexplate Wallbreakers), you'll have that many additional combat phases, but your attacking creatures are untapped only during the current combat phase
While the card creates some interesting decision-making on your opponents part, it doesnt seem like a great inclusion outside of dedicated tap decks
(6/18/2021) You must pay the costs for the chosen card, but you cast the copy as the ability resolves, which may not be a time that you could normally cast that card
Kutzil, Malamet Exemplar Kutzil, Malamet Exemplar takes Grand Abolisher a step up with more power and a potent card draw ability that pairs well with the various buffs Selesnya offers its creatures
Adding an Arcane Signet for some extra ramp and easy mana fixing is an easy one, as the stock precon doesnt include one
You have cards for every situation and just how you leverage them matters so much