I mean, Agent Frank HorriganAgent Frank Horrigan, Roalesk, Apex HybridRoalesk, Apex Hybrid, and Atraxa, Praetors' VoiceAtraxa, Praetors' Voice are all right there
The decklists are just here to highlight what kinds of cards you can expect in a given archetype
Wherever you decide to shop, the important thing is to enjoy the process and have fun adding to your collection
The original text of Cortexic Jellyfishs first ability is unclear, and there are different possible interpretations of it Whenever Cortexic Jellyfish attacks, it doesnt untap during your next untap step. Cortexic Jellyfish doesnt untap during your untap step. Cortexic Jellyfish doesnt untap during your untap step if it has attacked while on the battlefield. Although the last option is the most complex, and doesnt fit well into existing Magic card templating (with the possible exception of Palladia-Mors, the Ruiner)
It will only apply if the card loses indestructible before the end of the end step
If you do have ways of making it stronger, this can be an incredible way of setting up a big turn later on