To finalize the trend of economic inefficiency in its champions, the Fallen Kingdom has Elut-Bal. While definitely not economically efficient, his mere existence in your deck is a major threat to your opponent, especially to their summoner. Any friendly unit, for an expensive price, can become a 6/6. Which, thanks to Undead Archers may actually be harder to kill than 6 life would normally seem. You can even do something crazy like summon Elut-Bal, Blood Summon twice from him and surround the opponent’s summoner for the kill. While something like that may seem unlikely, the constant threat of that happening is a real problem for your opponent, sometimes demanding sub-optimal plays from them to compensate for this potential threat.