Dunno about citrine, because Im new to gem knights ( well, they say it works as mighty slugger ).
Nerokius is exactly like this one, however this card is a synchro monster, which makes it way easier to summon due to special summoning, graveyard to field, traps such as powerful rebirth, etc.
How can you even compare those with a generic synchro monster that you can splash into any synchro deck that can go into a Level 5 play? Nerokius and Citrine only work in their specific deck, this one is a viable option for a lot of decks
literally happens to every card that is more generic in requirements.
Also the fact nerokius needs 3 monsters in a 3 monster field game. Come on think already.
With card such as unknown synchron, this card can be splashed in almost every deck with generic 4* monster. This card and catastor will be a must have card for almost every deck in certain situation.