This power comes from her hand trap effect, where, if your opponent activates an effect with one of three conditions (add a card from Deck to hand, Special Summon from Deck, or send a card from Deck to graveyard and no, I will not call it GY), you can counter with Ash , who negates that effect
Tea: They've been at it for hours
If you can play a good interactive card that can act as a backup support card every now and again then you have a more consistent and more powerful deck
The other five are known as wedges , and get their names from the five clans of Tarkir in the Khans of Tarkir block (2014)
then check out its casting cost to decide if you want to play it regardless
I wanted to somehow equate this to a number of rounds in a tournament, but there is such a huge variation between formats (and even between decks) that I gave up