You always have a soft spot in your heart for the first rainbow deck you built. Mine was slivers. I love slivers for a lot of reasons. They play to the battleship nature of commander that I love. There are epic combats with tons of slivers that are all buffed beyond recognition by all the other slivers that are out. There are janky combos where slivers bounce each other back and forth and wipe the board or blow out opponents with ETBs.
My sliver deck is not my most powerful deck, but it is the one that has remained the most fun to play. There are so many ways it can win and it never wins the same way. I've tweaked it's power level down to make it more interesting, reducing the amount and nature of tutoring in it mostly.
I have a deck building addiction so I rarely return to a theme, but I've been missing my Slivers, so I decided to rework the deck a little bit. It's been about a year and there are both new cards to add and changes to the way I approach deck building.
Lowering the Ramp Curve
OUT
One of the biggest improvements to my commander game is dropping most of my ramp down to 2 CMC or less. These two are great ramp, but by the time I can get them out, it's probably too late. Also, they're way too juicy of targets for removal.
IN
Arcane signet was a godsend for this WUBRG deck. I should have had Fellwar stone in from the start, but both of these help me fix my mana and ramp for only 2 cmc.
Too Many Color Pips
OUT
I had powered down the deck previously and switched to these two card draw sources, but after some play, it's a little too much too ask a WUBRG deck to have 2 of the same color pips early on so I'm upgrading them.
IN
These two sources of card advantage are easier to cast and fit the feel of the deck. I wanted most of my card advantage to be creature based as the deck is all about slivers. Getting the secondary way to return slivers from the graveyard is definitely needed as my boards are often getting wiped and sometimes the sliver you need is dead.
Not What's Needed
OUT
I've got a lot of slivers. Some of them just don't get much play. Brood Sliver was one of those. Too big. Too slow. Too expensive.
Some cards are better off in CEDH. This looks like free ramp, but at the cost of a card, it's not worth it. I love this deck because it's battle cruiser magic. The card disadvantage has led me to not play this card more often than I would like. Each sliver in my deck has a specific use case so there's really nothing to replace it once chrome mox has exiled it.
I already have a lot of impulsive draw type effects in the deck and the cost of activation for icon of ancestry was way too high. There are better ways to give my team +1/+1 too.
IN
There was not enough interaction in this deck and the new angelic ascension is better than most of my other options. I opted for it over Swords to Plowshares for the flexibility to hit plainswalkers and Path to Exile because a 4/4 Angel is less of a benefit than an extra land in play.
Sometimes there is an omission so glaring that it prompts you to reevaluate a whole deck. Seriously, there was no reason this shouldn't have been in from the start.
This deck has the most janktastic WUBRG mana base, but even it falls short sometimes. Best to have some insurance. Worth the extra 1 cmc over my other rocks.
MANA BASE UPGRADES
I've got so many sac lands in this deck as I have so many janky cards that care about what's on the top of my deck. This one wasn't out when I made the deck and was worth losing a swamp for.
New Commander
This deck was originally commanded by Morophon of the Boundless, but he was too expensive to cast and I was regularly getting WUBRG available to me early on. Then it was commanded by Sliver Overlord, but then the deck became too repetitive as I would always search up the same slivers in the same order. Sliver overlord lets the deck regain some randomness while helping keep it safe from board wipes, helping me get to the best moments this deck can provide where a huge board of random slivers goes around wiping out all other life on the plane.
Decklists
Going back to review my old decks is an exercise I need to start doing more often. I think this deck is getting close to the power level and the play style I like. There's plenty of fun cards that are just janky, but allow for some very entertaining moments. I love it when descendants path gives me a free First Sliver that cascades into a Cloudshredder Sliver and suddenly someone's going to die to my hasty flying horde. Or when Morophon is out and I just start dropping slivers for free until I need another playmat to fit them all. Designing for the best experience isn't always designing for the most powerful deck. One day this deck might even be done. Today is not that day.