You have to have a deck of 99 cards plus your commander
Courtesy of Wizards of the Coast (WotC), check out the black mythic rare modal double-faced card from Zendikar Rising Agadeems Awakening
You can do this while the job select ability is on the stack (see the following section for details)
And, of course, there's the companions - a mechanic so powerful it needed an errata and still has proven to be too strong
It can be useful in postboard games when topdecking Reunion can give you a much needed boost after opposing graveyard hate wipes your resources Cathartic Reunion and Thrilling Discovery The majority of times, both cards will do the same: discard two and draw three cards, resulting in dredging up to fifteen cards in the best case scenario
Then you can tap him for three to draw, discard, and then if it was an artifact, you can exile it and make an 0/2 Thoper artifact copy of that artifact with flying