The Curious Obsession suggestion is only good with the added 1-drops.
Regarding the Copter you probably don't want to crew it with your big flyers meaning there aren't that many good options to crew it early making it not as good in this deck imho.
The Wand doesn't seem good enough imho, it is too slow and doesn't really fit the tempo plan that the deck seems to be going for.
Smuggler's Copter is banned now, anyways, as we all thought it was going to be; but he was saying Copter is bad when half the creatures in your deck are on par or bigger than Copter. You wouldn't crew it with Tempest Djinn or Sphinx of Foresight, for example, as you'll be losing out on damage. You might also just have it sit out there and you not have any creatures to crew it until you hit 3 or even 4 mana. I also think Tempest Djinn and Mutavault are at direct odds with one another. One needs UUU to be cast, the other taps for 1. One gets stronger the number of islands you control, one is not an island. There will be games where you will draw 2 Islands, 3 Tempest Djinn, and 2 Mutavault and just lose.
4 dive down
4 opt
4 siren stormtamer
4 spell pierce
(8) 2cc
4 merfolk trickster
4 smuggler’s copter
4 brazen borrower
4 tempest djinn
(4) 4cc
4 sphinx of foresight (leyline)
(24) land
20 islands
4 mutavault
4 ceremonial rejection
4 tidebender mage
3 negate
3 transmogrifying wand
1 sorcerer’s spyglass
This deck is untested. I won't get a chance to tune it either as my LGS won't run anymore pioneer in the forseeable future.
limited - https://www.youtube.com/watch?v=Vkfx2kA8gok&feature=emb_logo
limited - https://www.youtube.com/watch?v=I3RYiZJFCK0
limited - https://www.youtube.com/watch?v=j18HlKybrm8&feature=emb_logo
standard - https://www.youtube.com/watch?v=JiAEzfAgpbI&t=1s
standard - https://www.youtube.com/watch?v=3vNr_4ubfMg&t=1s
standard - https://www.youtube.com/watch?v=EJcwpxraL-g&t=1s
modern - https://www.youtube.com/watch?v=V8MyVNLVYNw&t=1s
modern - https://www.youtube.com/watch?v=4-M5ffoArnY&t=1s
modern - https://www.youtube.com/watch?v=x_yQEBOPi_w&feature=emb_logo
extended - https://www.youtube.com/watch?v=qLpUB9zpyr4&feature=emb_logo
I'd suggest Curious Obsession for card draw.
You have plenty of 1-drop options with unblockable to put it on like: Slither Blade, Mist-Cloacked Herald and Triton Shorestalker.
Another good 1-drop option is Spectral Sailor which has flash + flying and can be a late game mana sink to draw cards.
You probably need more ways to deal with creatures even temporarily like: Unsummon, Unsubstantiate/Blink of an Eye or Warrant // Warden.
Reality Shift can also be used to shrink creatures down to 2/2's (there is also Rapid Hybridization).
MonoU in general hardly runs removal main. My SB Transmogrifying Wand isn't perfect but it's the bet I can come up w/.
limited - https://www.youtube.com/watch?v=Vkfx2kA8gok&feature=emb_logo
limited - https://www.youtube.com/watch?v=I3RYiZJFCK0
limited - https://www.youtube.com/watch?v=j18HlKybrm8&feature=emb_logo
standard - https://www.youtube.com/watch?v=JiAEzfAgpbI&t=1s
standard - https://www.youtube.com/watch?v=3vNr_4ubfMg&t=1s
standard - https://www.youtube.com/watch?v=EJcwpxraL-g&t=1s
modern - https://www.youtube.com/watch?v=V8MyVNLVYNw&t=1s
modern - https://www.youtube.com/watch?v=4-M5ffoArnY&t=1s
modern - https://www.youtube.com/watch?v=x_yQEBOPi_w&feature=emb_logo
extended - https://www.youtube.com/watch?v=qLpUB9zpyr4&feature=emb_logo
Regarding the Copter you probably don't want to crew it with your big flyers meaning there aren't that many good options to crew it early making it not as good in this deck imho.
The Wand doesn't seem good enough imho, it is too slow and doesn't really fit the tempo plan that the deck seems to be going for.
MonoUleyline 2.0
4 dive down
4 opt
4 siren stormtamer
4 spectral sailor (credit to D90Dennis14)
(8) 2cc
4 merfolk trickster
4 smuggler's copter (now w/spectral sailor)
4 brazen borrower
4 tempest djinn
(4) 4cc
4 sphinx of foresight
(24) land
20 islands
4 mutavault
4 ceremonial rejection
4 negate
4 tidebender mage
3 transmogrifying wand
limited - https://www.youtube.com/watch?v=Vkfx2kA8gok&feature=emb_logo
limited - https://www.youtube.com/watch?v=I3RYiZJFCK0
limited - https://www.youtube.com/watch?v=j18HlKybrm8&feature=emb_logo
standard - https://www.youtube.com/watch?v=JiAEzfAgpbI&t=1s
standard - https://www.youtube.com/watch?v=3vNr_4ubfMg&t=1s
standard - https://www.youtube.com/watch?v=EJcwpxraL-g&t=1s
modern - https://www.youtube.com/watch?v=V8MyVNLVYNw&t=1s
modern - https://www.youtube.com/watch?v=4-M5ffoArnY&t=1s
modern - https://www.youtube.com/watch?v=x_yQEBOPi_w&feature=emb_logo
extended - https://www.youtube.com/watch?v=qLpUB9zpyr4&feature=emb_logo
limited - https://www.youtube.com/watch?v=Vkfx2kA8gok&feature=emb_logo
limited - https://www.youtube.com/watch?v=I3RYiZJFCK0
limited - https://www.youtube.com/watch?v=j18HlKybrm8&feature=emb_logo
standard - https://www.youtube.com/watch?v=JiAEzfAgpbI&t=1s
standard - https://www.youtube.com/watch?v=3vNr_4ubfMg&t=1s
standard - https://www.youtube.com/watch?v=EJcwpxraL-g&t=1s
modern - https://www.youtube.com/watch?v=V8MyVNLVYNw&t=1s
modern - https://www.youtube.com/watch?v=4-M5ffoArnY&t=1s
modern - https://www.youtube.com/watch?v=x_yQEBOPi_w&feature=emb_logo
extended - https://www.youtube.com/watch?v=qLpUB9zpyr4&feature=emb_logo