Myr Retriever: a deterrent if someone wants to block it, and it they do and it dies, you can get one of your much better artifacts out of the graveyard
Step 5: Immediately take the portal again this will bring you back to the 5th floor right by the Team Rocket Grunt
Your Relentless Rats gets stronger the more copies of it you have in play, so if you have six Relentless Rats, each one of them is getting +5/+5, making them a three mana 7/7
From just looking at Mew ex, having a solid amount of HP for a Basic Pokemon, an Ability that can draw extra cards and a free Retreat Cost is a huge flex
These effects can be informally categorized based on classifications of monster effects: Continuous-like Effect: An effect that continuously applies while the Trap Card is face-up on the field
It makes beating sweepers trivial, and manifests creatures on its own, which can become cheap sources of huge lifegain with Mastery of the Unseen even when you never have time to activate it