The spirits it creates having menace also makes them effective attackers, especially if youre giving them powerful auras
It's important to note that Caesar, Legion's Emperor itself doesn't need to attack, only see a creature attack to sacrifice a creature to trigger its effect
In fact, I think many of the cards are actually pretty bad in many decksremember Wrath of God from last time
The Kyogre cards design reflects its powerful abilities in the Pokmon games, with high attack and defense stats and the ability to summon powerful rainstorms
I think the best home for this is in older formats, where its comparable to Eidolon of the Great Revel, a card that has been a staple in burn decks ever since it got printed
This, for many people, is the scary part