TL;DR: Enough -strength for Molecular prime -60%, or enemies 60% Faster, Enough Duration for Null Star 90% damage reduction (Max) and higher area covered.
Recommended 1 Archon Crimson Shard 10% Duration and 4 Archon Azure shard , x2 50 Mana and x2 Mana/Armor/Health to make the build compatible with the slow counterpart.

Slow Nova Build:
https://overframe.gg/build/379910/

There are two goals to achieve as a fast [Nova Prime]: Duration +300% and Strength 10%. Be ready, as I'll guide you in how to achieve the max benefit of your antimatter lady and become the Crème de la crème [Nova Prime] you always wanted to be.
The fast [Nova Prime] build consist, as the name indicates, to speed up enemies with Molecular prime and is mostly used to speed up defense missions. But why Duration and Strength are important for the Fast Build?

Molecular prime releases a Speed up(Fast Nova Prime) wave that starts at 5 m from Nova and it propagates to the enemies at a 5 m / s rate during 6 s (base max rank). Range does not increase the expansion of the wave, BUT duration does.
Higher durations = Longer distance the wave covers, hence we are aiming at more than 300% duration.
The amount of strength Nova has at the moment of Molecular prime activation decides the enemy movement speed/attack speed modifier. With a base strength of 100%, the enemies are 30% slowed. The maximum slow debuff cannot exceed 75%, which is reached with 145% strength.
On the other hand, if strength goes below 70%, enemies will be faster instead (Fast [Nova Prime]).
In order to achieve the 10% strength (60% faster enemies) you have to make use of [Overextended] and [Power Donation].

Null star creates 6 (Base max rank) antimatter particles that orbit around yourself and only attack if enemies are located at 12 m (Base max rank) away, every second. When the particles are orbiting the warframe, each one of them grant 5% Damage reduction to the health, with a Max damage reduction of 90% with 20 particles.
The amount of particles created is affected by Duration and in order to create the 20 particles, a Duration of 300% is required.
For this build, we are using 282% duration through mods, 36% with Molt Efficiency and 10% with a single Crimson Archon Shard 10% Duration for a total 328% Duration, which give us the 90% damage reduction and increased the total area covered by molecular prime.

For the subsumed abilities, I recommend Dispensary in antimatter drop.
For Exilus slot, [Endurance Drift] is a nice QOL mod to have. An options would be [Escape Velocity] (If you didn't remove Wormhole).

Aura Mod is [Power Donation] and the Aura Forma used here is to make this build compatible with Slow [Nova Prime] build. [Power Donation] takes 30% of your strength and gives it to your allies, leaving you with a total of 10% strength, or 60% faster enemies. This is one of the reasons 2 Fast Novas are not recommended as they cancel each other this aura mod.

[Molecular Fission] is required to have Null Star active almost 100% of the time.
[Adaptation] is a very useful mod to reduce damage.
Arcane Energize so you never run out of mana, can be changed for a more offensive arcane according to preferences.