Willbreaker - Can use Derevi's tap ability to steal a bunch of creatures.
Galecaster Colossus - With any board state to speak of, hard lock opponents.
Krosan Grip - Top 3 green removal spell.
Seedborn Muse - Best untapper in the game.
Avacyn's Pilgrim - Mana dorks and rocks are very strong with Derevi, can use twice.
Llanowar Elves - See Avacyn's Pilgrim.
Elvish Mystic  - See Avacyn's Pilgrim.
Thassa, God of the Sea - Make creatures unblockable for more untapping.
Consecrated Sphinx - Best repeatable blue card draw creature.
Stoic Angel - This is a really brutal stax card in Bant. Ignore if not playing stax control, probably.
Wizard's Retort - If you have Derevi in play this is another copy of Counterspell (the best counter in the game). Better than Bind, Brainstorm, DIsmiss, Swan Song at least.
Gilded Lotus - Untap this for 3 free mana, see Avacyn's Pilgrim.
Darksteel Ingot - See Avacyn's Pilgrim.
Dowsing Dagger - Your deck has ways of sneaking in creatures. Sneak this in to get a land version of Gilded Lotus.
Panharmonicon - If you're going down the flicker road, this is great. If you're not, pass.
Skyshroud Claim - This is one of the best ramp spells in the format and just got a reprint. Definitely better than Explosive Vegetation if you have any duals, probably better than Kodama's Reach and Cultivate.