The biggest weakness of the Sasaya deck is enchantment removal. Fortunately, land tapping doesn't involve the stack, so Seglagg can use the last bit of mana before Medrash goes away. He no longer has any mana to respond to anything new. Fortunately, because of Reliquary Tower, Seglagg will have no problem coming up with 7 or more lands when he plays Medrash again.

(I also forgot to mention Yahenni got a whole lot of +1/+1 counters from last page.)