You got a lot of answers. Archive this build or throw both of those items. I would like to see your match history too.

i like the concept of your guide to provide a more basic version of sivir to play for people who aren't good at playing a more optimal build for sivir. it's pretty cool and is probably going to be a lot of help to newer players.

now what i don't agree with is trying to defend the item build when people are trying to help you optimize. it's true muramana and SotD aren't going to be the best items for sivir. you should be taking a more "this build isn't the best, it's the easiest" defense route. accrediting the build with your rank in league really isn't helping you are all, its a peeve of mine to see. bluntly, gold sucks. I'm gold too, take it from me. absolute garbage.

imo the reason you're seeing wins with the build is because people aren't used to carries with as much burst as this build can put out and just flat out dont expect it. the enemy team can easily take advantage of your slow ramp up time thru early and mid game and shut you down to the point where you just might not reach endgame despite the 1k cost difference.

Thank you all for taking the time to consider my build. I' ve heard lots of negative critique so far, some precise, some just random spamming of doesn´t work. So I` ll make a longer reasoning for my build here.
First off I use this build myself and made it from Silver to Gold 3 with it. So it definitly is not "bronze trash".
To the Items:
Manamune - common critique here from the comment section:
There are better Items, like Infinity Edge. I dont actually know if thats right. It could be. But rushing Tear of the Goddess early on transforms your lane into a snowball lane(how to play is written in the guide). Since Tear of the Goddess is pretty powerfull in itself you are left with the choices of selling it or upgrading it, which i prefer.
Sword of the Divine - common critique not as good as Phantom Dancer or Statikk Shiv:
I have explained already why I use this Item in my guide, therefore I will not repeat it here. Keep in mind however that you dont need to activate it on the first enemy you attack, just wait(or move in) till you attack the squishies.
Last Whisper - critique there are better items like Blade of the Ruined King:
You need armor pen as ADC or you will get zoned in teamfights by some toplaner stacking armor. Last Whisper is a "must have item" , should add it to the core build.

Lastly no Mid to Late Game DMG:
There is a whole section in the guide comparing this build to a standard build. And yes late Game your DMG output dropps off. But following this build early and midgame you almot always have acquired a big enough gold lead to compensate for it. It'll be through more cs or kills. And if your one of the players prefering Infinity Edge over Muramana you most likely can replace your muramana with IE before the other carry has finished his build.

Mid game damage? Late game damage?
I have no idea why some people are saying that you're focusing too hard on that here because you don't have any mobility, survivability OR damage. Nothing. Zilch. Nada. Just random items put on a champ.

Manamune? On an ADC? You're not playing Blitzcrank, you're playing Sivir. You don't need Manamune/ Muramana as stated before.

Sword of the Divine is a garbage grade item. Right up there with Mejai's Soulstealer and Wriggle's Lantern.

Last Whisper is situational and can be replaced with something better. Maybe Blade of the Ruined King for some more, y'know, damage in this god forsaken HP stacking meta.

You'll poke the enemy a few times, tickle them a bit, then you'll be squashed like a bug. This build needs an overhaul.

I'm only repeating what said above, but that's pretty much how glaring the issue is.

^Precisely. You get burst for 3s, but then lose it (and then some) for 1 minute.

^ It isn't even optimalised for mid/late game damage. The build lacks any form of crit which sword of the divine doesn't make up for. 3 crits without IE is about 800 damage before armor reductions, and that's all the damage you'll do for 60 seconds because the 45% attack speed from sword of the divine gets deactivated when the active is on cooldown.

The part about Muramana not being a strong item is that it completely sacrifices your early game - Tear of the Goddess provides no early stats. It completely weakens your level 6, which is easily Sivir's earliest power spike. Late game, it's not so much a problem, but the item slot is completely sacrificed for the Lifesteal of Bloodthirster or the crit bonus on Infinity Edge, which Muramana doesn't give.

Sword of the Divine doesn't provide the same constant mobility, AS and crit chance that Phantom Dancer/ Statikk Shiv provides. Without your ultimate, your mobility is completely shot and makes you a sitting target for any burst mage or assassin.

To put it simply, the issue with your build is that it isn't balanced enough. Too much focus has been put onto mid-late game damage without considering early game, overall mobility and consistent damage.

I will elaborate.
1st: tear into muramana(2100) is almost equal to vamp scepter+BF(2350). muramana's AD boost right off the bat is somewhere around ~ 40 in total, below BF even.
2nd: tear = push the lane without a care to win lane through poke. I don't do a poke fare with any adc with tear on, I try to outright kill them, you will be blown to bits by normal build on any popular adc. You got no sustain so even if I don't catch you good, I could still maim you big time and force you to back.

SotD? You're not playing dominion. Sivir is not one to make use of this anyway. I really don't wanna explain this one. It just never suit adc. The active could be cool but you need to get the whole thing for it to work, while most other stop at getting zeal then opt for LW... And after 3 hits, you will be sitting duck, let alone muramana+SotD give off so much damage... Seriously, the burst isn't worth it on a guy you expect to have sustained and ARMOR PIERCING damage.

Build isn't really viable. Stick with the standard BT-Shiv-LW/IE build for optimized damage.

What exactly is the part that does not work with muramana on sivir ?
Is the 700 gold for Tear of the Goddess in your opinion too much for an item that does not provide combat stats ? The guide provides a chapter in which the differences between a standard ADC build and building muramana on sivir is discussed. I am currently in Gold IV, always build Sivir following the guide and win consistently with it.
Sword of the Divine gives you attack speed and burst, which sivir does not have in her general ability kit. So if you want to elaborate why this Item should be trash I would enjoy listening.

No. Just dont. Muramana on Sivir doesnt work and Sword of the Divine is a trash item in general. It gives you nothing.