Before we actually get started there is some general deck building construction as far as EDH/Commander goes. No matter what you end up with, the following is a good guideline for getting your deck to feel like it's functioning properly:
1)Play at least 38 lands
-I know it's hard to not shove all the cool spells ever into your deck, but you really need a certain amount of lands in order to consistently play all your cool spells.
2)Play about 10 card draw effects. (stuff like
Azami, Lady of Scrolls which came in your preconstructed deck)
-EDH/Commander, by its very nature is a high variance format with only one copy of each of 100 cards (not counting basic lands) it's important that you be able to dig through your deck to find the appropriate tool for your situation and to make sure that you don't run out of gas.
3)Play about 10 mana ramp effects. (stuff like
Darksteel Ingot which came in your preconstructed deck)
-EDH/Commander is a format dominated by who can do the biggest/most things in their allotted turns, and the more mana you have, the bigger/more things you can do.
4)Play about 5 board wipe effects. (stuff like
Kindred Dominance which came in your preconstructed deck)
-As you have noticed in your games already, things can get rather out of hand in a game of EDH and often times the board needs to get wiped clean. Most of these will want to hit creatures, but you should also aim for at least one of your board wipes to hit artifacts and/or enchantments.
Nevinyrral's disk, which also came in your preconstructed deck, hits all three so that's pretty sweet.
5)Play about 5 spot removal effects. (stuff like
Terminate which came in your preconstructed deck)
-Similarly to board wipes, most of these should hit creatures, but again you'll want at least one of these cards that hit artifacts and/or enchantments and at least one that can hit lands. You don't need repeatable land destruction, but sometimes there are lands that just need to die (stuff like
Gaea's Cradle should generally get removed whenever the opportunity arises). Fortunately for you
Chaos Warp, which also came in your preconstructed deck, covers all the bases so you are fine there.
You will find that there are occasions to break these guidelines either by going over or under the recommended values, (for example I have an
Arahbo cat tribal deck that runs only 35 lands because the average casting cost of the spells in it is pretty low) but this is a very solid starting point.
Below you'll see the deck laid out in my preferred format: Creature vs Non-Creature and in ascending order of casting cost
Commander (1):
1 x
Inalla, Archmage RitualistCreature (31)
1 x
Apprentice Necromancer1 x
Harbinger of the Tides1 x
Nin, the Pain Artist1 x
Nivix Guildmage1 x
Izzet Chemister1 x
Merchant of Secrets1 x
Portal Mage1 x
Sea Gate Oracle1 x
Serendib Sorcerer1 x
Shadowmage Infiltrator1 x
Archaeomancer1 x
Corpse Augur1 x
Kess, Dissident Mage1 x
Magus of the Abyss1 x
Mairsil, the Pretender1 x
Marchesa, the Black Rose1 x
Vindictive Lich1 x
Azami, Lady of Scrolls1 x
Bloodline Necromancer1 x
Body Double1 x
Havengul Lich1 x
Izzet Chronarch1 x
Mercurial Chemister1 x
Puppeteer Clique1 x
Taigam, Sidisi's Hand1 x
Arcanis the Omnipotent1 x
Etherium-Horn Sorcerer1 x
Magus of the Mind1 x
Niv-Mizzet, the Firemind1 x
Vela the Night-Clad1 x
Galecaster ColossusNon-Creature (30)
1 x
Curse of Opulence1 x
Sol Ring1 x
Fellwar Stone1 x
Go for the Throat1 x
Into the Roil1 x
Mirror of the Forebears1 x
Rakdos Charm1 x
Reality Shift1 x
Terminate1 x
Chaos Warp1 x
Commander's Sphere1 x
Crosis's Charm1 x
Curse of Disturbance1 x
Curse of Verbosity1 x
Darksteel Ingot1 x
Polymorphist's Jest1 x
Shifting Shadow1 x
Unstable Obelisk1 x
Worn Powerstone1 x
Memory Plunder1 x
Nevinyrral's Disk1 x
Silumgar's Command1 x
Cauldron Dance1 x
Comet Storm1 x
Opportunity1 x
Spelltwine1 x
Kindred Dominance1 x
Necromantic Selection1 x
Decree of Pain1 x
Clone LegionLand (38)
1 x
Exotic Orchard1 x
Path of Ancestry1 x
Command Tower1 x
Crumbling Necropolis1 x
Vivid Crag1 x
Vivid Creek1 x
Vivid Marsh1 x
Dimir Aqueduct1 x
Dismal Backwater1 x
Izzet Boilerworks1 x
Jwar Isle Refuge1 x
Rakdos Carnarium1 x
Swiftwater Cliffs1 x
Evolving Wilds1 x
Grixis Panorama1 x
Terramorphic Expanse1 x
Mystifying Maze1 x
Temple of the False God10 x
Island6 x
Swamp4 x
MountainLands: 38
Good number though I can think of a few upgrades in terms of selection that might fit your budget.
Card Draw: 16
You have LOTS of card draw. I could definitely see cutting some of these to find room fill in some of your deficiencies.
Nin, the Pain Artist <- note that this will overlap in the spot removal category, a single card can fill multiple roles
Nivix Guildmage <- Yes it's not putting you up a card, but it will help you find more relevant cards if you have some dead ones
Merchant of SecretsSea Gate OracleShadowmage InfiltratorCorpse AugurAzami, Lady of ScrollsMercurial Chemister <-overlap with spot removal category
Arcanis the OmnipotentEtherium-Horn Sorcerer <- not explicitly draw, but a free spell from your deck is similar enough
Magus of the Mind <-not explicitly draw, but multiple free cards from your deck is similar enough
Into the RoilCommander's Sphere <-overlap with mana ramp category
Curse of VerbosityOpportunityDecree of Pain <-overlap with board wipes category
Mana Ramp: 8-ish
It's a little low and I DEFINITELY have some ideas on what to put in.
Curse of Opulence <-I'm not too keen on the curses help your opponents too and this is only temporary ramp to boot
Sol RingFellwar StoneCommander's SphereDarksteel IngotUnstable ObeliskWorn PowerstoneTemple of the False God <- Yes a land can count towards mana ramp if it is able to provide you with more than one mana
Board Wipes: 4
Close, but I'd like to add one more to be safe
Nevinyrral's DiskKindred DominanceNecromantic SelectionDecree of PainSpot Removal: 15
Good GRAVY there is a lot of spot removal here. We can most certainly cut large swaths of this away
Nin, the Pain ArtistMercurial ChemisterTaigam, Sidisi's HandNiv-Mizzet, the FiremindGalecaster ColossusGo for the ThroatRakdos CharmReality ShiftTerminateChaos WarpCrosis's CharmUnstable ObeliskSilumgar's CommandComet StormMystifying Maze <-No it's not permanent removal, but it does a real good job of making threatening things look somewhere else
!
.
). Chaos warp though. That card has gotten me into a whole horde of trouble with the dragons deck. I get rid of something slightly useful to them and then they pull a very high cost amazing dragon that costs too much for them to get and place it for free.