Boomerang - More flexible than Vapor Snag, and can hit anything. Costs 1 extra mana, and doesn't cause the 1 life loss (doesn't really matter), so I am wondering if the higher cost is worth the higher flexibility. Can bounce lands, which is annoying, and can also give us a second chance to counter an enchantment, or artifact, or anything that isn't a creature, that may have slipped under our radar, or made it on board before we are set up. Definitely considering this card.
Rune Snag - Basically Mana Leak, only they have to pay 1 less, but it builds up as the game goes on. The 1 mana difference can matter, and my end all statement will be, it depends on your meta. I will be keeping Mana Leak because I am lazy, and it is less risky.
Lorthos, the Tidemaker - A possible replacement for Inkwell Leviathan, and has more impact. The problem is though, it has no protection. Inkwell Leviathan has shroud, whereas Lorthos, the Tidemaker does not. He does, however, have the option to tap out our opponents lands, which can effectively be shroud, because they can't cast anything. The danger though is the turn that he comes in, because he is vulnurable when we have very little mana after spending 8 to play him. He is a possibility, and honestly seems more interesting than Inkwell Leviathan. I'll definitely be testing him out.
Peek - Cantrip that lets us know what's coming, and if we should play a wall, or hold the mana open for a counter. Not positive on this one, but it's intriguing.
Enclave Cryptologist - I just love level up cards, and I'm wondering if this one will be an actual useful hand filter engine, and eventually straight up card draw. It's cheap mana cost and low level up cost is baiting me in to test it out. Maybe I'll put it in a commander deck to appease my needs.
Blue Sun's Zenith - Fun to keep all your mana open and scare them into not playing anything and then drawing a load of cards on their end step. And then maybe doing it again if I get lucky.
Think Twice - Personally, this card confuses me. I think it's good, I think it's bad, I can't make up my mind. There is synergy with Mana Leak and Dissolve, and I know other people run it, so I was thinking of testing it out.
Dismiss - Hey, that's some nice card advantage. CMC is the issue though.
Inkwell Leviathan - I decided to take this one out, as I simply could never cast it due to it being 9 mana to play. Hopefully Guile or something else can take its place as one of my wincons. I still like the shroud though.
Telepathy - Same with Peek, It's nice to know what you're up against.
Engulf the Shore - Probably a better AEtherize, but I'm going to test it before I put it in.
Tempest Djinn - Starts off as a blocker, and graduallly gets bigger, up to the point where it can win the game if you have board dominance
Plumeveil - Surprise 4/4 blocker