This isn't a huge ask for an already-aggressive red deck, and getting two treasure every turn from as early as turn three can give players a huge advantage as the game goes on
Cloudshift specifically returns the creature to the battlefield under your control, so the creature always enters under the control of the player who cast Cloudshift, where its no longer associated with the mind control effect that originally took it
For Ruby/Sapphire, the foil Belle Mechanic Extraordinaire only has 3 targets to Shift onto
I think his point is that, since it doesn't say to shuffle, it has a bit of a use in that you can know what cards he's going to get(until he shuffles his deck in some way)
Card Images Product Information Pokemon Sun & Moon Crimson Invasion Booster Box Product Summary: The tale of fierce Ultra Beasts unfolds across the Pokmon TCG landscape in the Sun & MoonCrimson Invasion expansion
The main line of play is simple but powerful: develop ink early with Sapphire, then drop mid-to-late-game glimmers that generate Lore more efficiently