I've only been playing magic for a few years so I realize there are tons of cards I don't know about, which is why I'm posting here looking on how to improve this deck/complete a sideboard before I go try to compete with it. I've always loved having a mill deck and it has drastically evolved from a hit or miss deck to a strong/annoying deck that my friends say is the best I've made. I've never bothered making a sideboard since I only play with friends, so any suggestions for that and/or the main deck are appreciated. I based the general idea of this from a deck I saw online and I had most of the expensive cards because I drafted the hell out of Modern Masters. If you start with PoE/Ghost quarter + archive trap + surgical extraction, this will ruin someone's day, not to mention if you have more than one surgical extraction or archive trap. Help me make it more nasty!

1 Dimir Aqueduct
4 Drowned Catacomb
4 Ghost Quarter
2 Glacial Fortress
6 Island
2 Plains
1 Sunken Hollow
2 Swamp
4 Archive Trap
2 Crypt Incursion
4 Dream Twist
2 Hedron Crab
1 Index
4 Jace's Phantasm
1 Jace, Memory Adept
2 Mana Leak
3 Memory Erosion
4 Mind Funeral
4 Path to Exile
3 Spellskite
4 Surgical Extraction

PS: New to this site so still in the process of entering my cards/making a tradelist - definitely open to trading if you have something that could help

Glimpse the Unthinkable -- Pricey money-wise, but worth it for a serious mill deck.

Also, Increasing Confusion comes to mind, mostly for its Flashback.

And while It's a bit slow for Modern, Keening Stone is just plain fun in mill. It generally finishes an opponent off by the time you're able to use it.