It's quite risky to let this creature resolve considering the controller has a living board wipe on the battlefield
As you'd expect for one-off cards, Heroes of the Realm pieces are illegal in all formats, with the special exception of Commander
Cyberdark Invasion Loading

The Deck Okay, here is the full decklist: Creatures (42) 1 Sol'kanar the Swamp King 1 Rune-Scarred Demon 27 Shadowborn Apostle 1 Grim Haruspex 1 Archfiend of Depravity 1 Kothophed, Soul Hoarder 1 Razaketh, the Foulblooded 1 Demonlord Belzenlok 1 Taborax, Hope's Demise 1 Jetmir, Nexus of Revels 1 Be'lakor, the Dark Master 1 Lord of Change 1 Plague Drone 1 Venomcrawler 1 Bloodthirster 1 The Balrog, Durin's Bane Lands (39) 14 Swamp 1 Polluted Mire 1 Grand Coliseum 1 Barren Moor 1 Murmuring Bosk 1 Arcane Sanctum 1 Crumbling Necropolis 1 Savage Lands 1 Exotic Orchard 1 Bojuka Bog 1 Command Tower 1 Unknown Shores 1 Opal Palace 1 Nomad Outpost 1 Sandsteppe Citadel 1 Opulent Palace 1 Desert of the Glorified 1 Survivors' Encampment 1 Path of Ancestry 1 Zagoth Triome 1 Indatha Triome 1 Ziatora's Proving Ground 1 Xander's Lounge 1 Raffine's Tower 1 Crystal Grotto 1 Barad-dur Spells (18) 1 Night's Whisper 1 No Rest for the Wicked 1 Bloodbond March 1 Damnation 1 Sign in Blood 1 Chromatic Lantern 1 Painful Truths 1 Anguished Unmaking 1 Secret Salvage 1 Thrilling Encore 1 Liliana's Contract 1 Arcane Signet 1 Skyclave Relic 1 Stinging Study 1 Echoing Return 1 Mask of Griselbrand 1 Blood for the Blood God

This one is all about contrast and proves that the price tag isn't as important as finding a card that resonates with you
There are no restrictions on the Level or type of the Monster selected