Sylvan Library Speaking of multi-format staples, Sylvan Library can even make the cut in Vintage, besides being often seen in cEDH
Channeler Initiate Channeler Initiate is a mana dork that adds mana of any color, and it has three uses
Theres a good chance combo decks would only get better with more tutor options at their disposal, too
This sometimes can result in you getting stuck for a few turns if you need an extra land that you know isnt coming
Creatures (18) 2 Autochthon Wurm 4 Allosaurus Rider 4 Simian Spirit Guide 4 Chancellor of the Tangle 1 Laboratory Maniac 2 Griselbrand 1 Rosethorn Acolyte Lands (14) Spells (28) 4 Nourishing Shoal 4 Serum Visions 1 Pact of Negation 4 Summoner's Pact 4 Manamorphose 4 Eldritch Evolution 1 Life Goes On 4 Neoform 2 Once Upon a Time Sideboard 9
However, it is important to mention that you are not really gaining any tempo from this trade, since when you take a card from your opponent's hand, they are never spending their mana to cast it (unlike a Counterspell, for example, which has a weird Time Walk effect on the opponent, since you not only stop the spell but also force your opponent to spend mana attempting to cast it)