Cards that gain passive life have been a part of Standard for a long time for good reason
While Thoughtseize-mode Devour Intellect with Tergrid, God of Fright out is insane, even without a Treasure, making our opponent discard a card for a single mana is still solid when we get to steal it if it's a permanent
Free, pinpoint interaction works well in many scenarios, plus it puts a creature in the yard for nothing
Captain America, First Avenger comes with two abilities - a Catch ability that allows the player to attach a target Equipment to Captain America and a Throw ability that Unattaches that Equipment and deals out damage equal to its mana cost
No one knows for sure how many of these are in existence, but it is believed less than 50 were distributed
Windy spawns his Circuit with a tornado