While a 4/4 for 3GG isn't marvelous, being able to double its power for 2GG as many times as you have open mana can make it extremely scary. Granted, it doesn't have trample on its own. Without help, it can be chump-blocked all day. But were it to gain trample and be played alongside say Xenagos, God of Revels or perhaps a Hunter's Prowess, it can kill a player very suddenly. It had some potential, that's for certain. Red-Green Monsters and Mono-Green Devotion were seriously good Standard decks at the time. With the amount of mana available to those decks, it seemed that it just might work at the top end of the mana curve.
Some Standard players indeed tried to make Heroes' Bane work. Cory Weber made the Top 8 of the 2014 Colorado State Championships with a copy of Heroes' Bane in his Devotion to Green deck. Early in 2015, Andreas Pettersson included a copy in his Devotion to Simic deck, which made the Top 8 at the Scandinavian Open in Stockholm. While this is pretty much the extent of any competitive play for Heroes' Bane, this was a card that people did try in their Standard decks.
Even well after its time in Standard, people still find uses for Heroes' Bane. As with many of the Hydras in Magic, Heroes' Bane shows up in plenty of Commander decks. While he sees play alongside a great many different Commanders, it should be little surprise that Xenagos, God of Revels is at the top of the list. While he made few waves in competitive play, Heroes' Bane has proved to be a versatile creature.