Aboleth Spawn copying the trigger from Eternal Witness, Solemn Simulacrum, Avenger of Zendikar, Sun Titan, and friggin Dockside Extortionist is going to be amazing
Put simply, Indestructible is a static keyword ability that stops a permanent being destroyed
His ability to ready up again twice per turn when chosen for an action or an item's ability seems fairly good to me as well, with a high ceiling for shenanigans, from my initial impressions at least
Even if you don't care about the value of the card, sleeves protect your game pieces, make it easier to shuffle and pick up
Retreat to Hagra This and Tunneling Geopede are close in my opinion
Modern storytelling is inclusive, respective of a global audience and aims to tell the story anew for a new generation