You can also activate Fateful Bite for 2 mana at sorcery speed allowing you to sacrifice Radioactive Spider to search your library for a Spider Hero card, reveal it, put it into your hand, then shuffle
Elvish Reclaimer has already made its way into many GB Slow Depths lists, and having four more souped-up copies of that effect only makes the game plan more consistent
I think the first version of Shah of Naar Isle had a template like "Echo Opponent draws three cards," but the rules and templating didn't like it that way, so they changed it to a 0 echo cost with a trigger
Sacrifice a Blood token and discard a card, and you can draw another card from your deck a useful tool if there's nothing in your hand that might alleviate your immediate predicament
Many tournament players use this method, keeping all their Standard-legal cards in a binder (or groups of binders)
As well as rewarding you for playing your Hydras, Selvala also provides you the mana through which to do it with her second ability, a mana ability that adds X mana, where X is the greatest power among creatures you control