On Running All Auras on One Character, and Mortal Conviction

So the way aura cost is calculated is: take the base, apply Reduced Mana and round down, then apply reservation reduction, then apply Mortal Conviction if applicable, then round up.

A level 20 Reduced Mana converts a 60% reservation (of which there are eight) into a 42%, and a 40% reservation (of which there is just one, Purity) into a 28%. Making it level 21 changes nothing, due to rounding down, so getting a +1 to all skills rare affix is irrelevant.

When the Blood Magic support gem is involved, an additional 196% mana cost multiplier is applied. In conjunction with Reduced Mana, this converts a 60% reservation into a 83% reservation, and a 40% reservation into a 55% reservation.

There are a total of 46% reduced reservation on the Passive Tree:
16% Sovereignty cluster
15% Charisma cluster
5% Leadership cluster
5% Influence cluster
5% in cluster near Smashing Blows

This 46% reduction turns a 42% reservation into a 23% reservation, a 28% reservation into a 16% reservation, a 83% reservation into a 45% reservation, and a 55% reservation into a 30% reservation.

The unique item Prism Guardian allows an additional 25% reduction, bringing the total for the three auras socketed in it to 71%. This turns a 42% reservation into a 13% reservation, and a 28% reservation into a 9% reservation.

So, with this unique alone, can we run all auras on one character? We can run four on mana, reserving 92%. Three more can be put in Prism Guardian, totalling 39% life reervation. We still have one 60% aura and Purity, and which would total another 75% life reservation. Since 39+75>100, this is impossible.

However, let's add another unique item: Alpha's Howl. This provides another 8% reservation reduction, bringing the total reduction to 54%. This converts a 42% reservation into a 20% reservation, a 28% reservation into a 13% reservation, a 83% reservation into a 39% reservation, and a 55% reservation into a 26% reservation. For the three auras in Prism Guardian, the total reduction becomes 79%, which can convert three 42% reservations into three 9% reservations.

Now can we run all auras on one character? It's unclear whether we can reserve exactly 100% of our mana, so for the sake of argument let's say it's impossible; we'll put four 60% auras and Purity, totalling 93% mana reserved. Three more can be put in Prism Guardian, totalling 27% life reservation. We still have one 60% aura left, which would reserve for 39%. 39% and 27% total 66%, leaving 34% life one which to squeeze the flat Clarity aura. We now have all ten auras on a single character, with essentially all life and mana reserved.

To complete the character, we'd add a Soul Taker axe (likely used with either Spectral Throw or Lightning Strike) and Shavronne's Wrappings to allow for ES-based survivability. Passive skill tree build. This would likely be combined with the Culling MF skeleton to provide a support character for dedicated group play. With 78% Increased Effect of Auras you Cast, having one in a party would be very handy, freeing everyone else from the need to run auras or magic find, while granting such benefits as 90% more Armour and 167-277 Fire damage.

Is the Alpha's Howl version of the build currently viable with Blood Magic? After all, the build plans run immediately next to the Blood Magic keystone.

With both a 54% reduction and Mortal Conviction's 30% less, a 42% reservation becomes a 14% reservation, and a 28% reservation becomes a 10% reservation. For the three auras in Prism Guardian, we have both a 79% reduction and Mortal Conviction, which can convert three 42% reservations into three 7% reservations.

Now can we run all auras on one character? After the three Prism Guardian auras, we still have five 60% auras and Purity, and 79% life remaining. 5 times 14% is 70%, plus another 10% is 80%, 1% too much. It's impossible for the Blood Magic version to run all auras simultaneously.

Now let's suppose that Mortal Conviction was buffed to 40% less. A 42% reservation becomes a 12% reservation, and a 28% reservation becomes a 8% reservation. For the three auras in Prism Guardian, each of the three 42% reservations becomes a 6% reservation.

So let's try running all auras again. After the three Prism Guardian auras, we still have five 60% auras and Purity, and 82% life remaining. 5 times 12% is 60%, plus another 8% is 68%, with 14% Life remaining. Blood Magic is at least now a consideration.

What would happen now if we took off Alpha's Howl, and used an ES helm instead, improving survivability? With a 46% reduction and 40% less, a 42% reservation becomes a 14% reservation, and a 28% reservation becomes a 10% reservation. For the three auras in Prism Guardian, we have both a 71% reduction and 40% less, which can convert three 42% reservations into three 8% reservations.

We can easily see that this is inferior to the 30% Mortal Conviction scenario which did not work. So a 40% Mortal Conviction would still be required to run Alpha's Howl.

What if Mortal Conviction was bumped to 50% less? A 42% reservation becomes a 12% reservation, and a 28% reservation becomes a 8% reservation. For the three auras in Prism Guardian, we convert three 42% reservations into three 7% reservations. After the three 7s, we have 79% life left, which is enough for 60% (5 times 12%) and an 8%, leaving 11% life remaining on which to squeeze Clarity (because why not?). Thanks to Soul Taker, skill costs would not be an issue, and the build would be capable of running an ES headpiece instead of the slightly less optimal Alpha's Howl, giving the build a significant power boost.