That isn't enough
If a creature with a boast ability is put onto the battlefield attacking, it was never declared as an attacker
However, we're still covering Heroes that would work great in Standard, Limited, and/or Commander
Creatures that ping each opponent when your other creatures enter, like General Kreat, the Boltbringer, are fantastic with Neriv

Abyssal Horror Ancient Cellarspawn Awoken Horror Call of the Nightwing Captain N'ghathrod Chainer's Torment Childhood Horror Corpseweft Cosmic Horror Creepy Crawler (playtest) Cryptborn Horror Dauthi Horror Defiled Crypt // Cadaver Lab Defiled Crypt // Cadaver Lab Delight in the Hunt Desperate Sentry Dimir Keyrune Dinrova Horror Emrakul's Evangel Endless Evil Enlightened Maniac Enslaved Horror Extricator of Flesh Extricator of Sin Flesh Carver For Each of You, a Gift Foul Emissary Gitrog, Horror of Zhava Grell Philosopher Hanweir, the Writhing Township Hidden Horror Hooded Horror Hook Horror Horror of the Broken Lands Horror of the Dim Howling Chorus Hunted Horror Hunted Lammasu Illithid Harvester Illithid Harvester Infectious Horror Jump Scare Krovikan Horror Lurking Evil My Forces Are Innumerable Nissa, Ascended Animist Otherworldly Outburst Phenomenon Investigators Phyrexian Rebirth Phyrexian Totem Pink Horror Profane Transfusion Psionic Ritual Restless Cottage Roiling Horror Skittering Horror Sludge Monster Spoils of Blood The Curse of Fenric The Final Days The Sentry, Golden Guardian There Is No Refuge Tomb of Annihilation Umbris, Fear Manifest Urabrask's Forge Wharf Infiltrator Woodwraith Corrupter Zellix, Sanity Flayer

The core gameplay follows the standard Lorcana rules and the challenge can be adjusted with four different difficulty levels