This set is surprisingly packed with interesting, powerful, and even just fun designs, given how parasitic the mechanics are (shrines, lessons, allies, etc.)
Unlike the Lord of the Rings set which felt like a normal set release in every way except its Middle-Earth setting the Doctor Who set is much smaller in scale
When Goblin Recruiter enters the battlefield, stack your entire deck. Yeah, that makes sense on a two-drop Or its unbelievably stupid, ruining any hope of playing a game (to say nothing of being completely busted)
Wall of Earth and Wall of Dust are pretty nice pieces of artwork, and I particularly like the heat-distorted mirage from Wall of Heat
It turns drawing a card into shooting a target for a damage, like normal, and then when anyone casts that spell
Chaos Warp Chaos Warps original claim to fame came in the early years of EDH, back when the only way to permanently remove a commander was tucking it into a library