Etymologically, it derives from ( mi- , a divinely or imperially honorific prefix), and / ( kamiko , kamuko , kanko , a Shinto priestess)
While Umi is active on the field, it becomes unaffected by other monsters effects - this protects it from monsters that target to destroy like [Blue-Eyes Alternative White Dragon]
This plays into their actual abilities, as all of the Trickstars are capable of inflicting whats called in Yu-Gi-Oh as burn damage - damage that occurs without actually using monsters to attack
Gameplay-wise, Dinosaur playstyles typically revolve around using high-ATK monsters and offensive Monster Effects, Special Summoning high-Level Main Deck monsters, effects that destroy friendly Dinosaurs for advantage, or advantageous effects that trigger from being destroyed by friendly cards
The more valuable cards that arent anywhere in that post would be the 1 of 1 steel printed Duel Monsters I tournament cards, you can see info on them in my Tokyo Dome link as well
This alone isnt great, but then you considered the fact that The Tyrant Neptune is a ten-star monster
