That's not how that works. 

Each ancient normally has 0.5% chance to pull a legendary, during a x2 event it is doubled to 1% chance to pull a legendary. Each shard only has 1% chance, so if you pull 100 shards that does NOT mean you have 100% chance to get a legendary, it means you have 100 shards that individually have 1% chance.

Also, please refrain from swearing.

In addition to what Harbby said, it is originally 8% chance to pull an epic so it is now 16%. Not 16% x 2.

Thank you, I couldn't remember off the top of my head.