In the past, the main concern was random, expensive, old Reserved List cards, which are comparatively easy to counterfeit
"into their owner's hand" is here for a reason
This is extremely useful when all you have are reactive cards and you need to find more proactive spells: You get to cast whatever you found useful in the 7-card batch, and regain your reactive cards at the end of the turn
Then you can discard two cards at the beginning of your first main phase to return this to your hand from your graveyard, which is card disadvantage naturally but with madness, lands, discard triggers like Archfiend of Ifnir, and loads more, it's got value
An attacking or blocking creature that phases out is removed from combat
Wingmantle Chaplain doesnt make wall tokens, but it makes Bird tokens equal to the number of defender creatures you control