well not really broken because of the mana cost, but you can use elvish pipers and such to try and get these out earlier
Once you get these two guys out you can draw all the cards you want
Elderscale Wurm 4GGG
Creature - Wurm (Mythic Rare)
Trample
When Elderscale Wurm enters the battlefield, if your life total is less than 7, your life total becomes 7.
As long as you have 7 or more life, damage that would reduce your life total to less than 7 reduces it to 7 instead.
7/7
and this:
Griselbrand 4BBBB
Legendary Creature — Demon
Flying, lifelink
Pay 7 life: Draw seven cards 7/7
you pay 7 life to draw 7 cards using griselband, and then the elderscale worm immediately puts you back at 7. Repeat this process as often as you like