Generic mod config for a Forced Slash Heavy Spam melee build, relying on slash procs forced by the heavy attack as the primary source of damage. This build will work for any melee weapon that fits the requirements, not just Reaper Prime.
Build Requirements:

• Have 16% CC or greater.
• The weapon must force a Slash Proc on its heavy attack.

Viral procs should be externalized, but are not necessary.

Mod Replacements:

• Swap the Primed Smite out depending on faction. Regular smites are acceptable.
• Primed Fury can be replaced with any attack speed mod, or outright replaced with something else.
• Primed Pressure Point or Condition Overload can be used in place of Sacrificial Pressure. This requires 19% base CC or greater, and is slightly worse in consistency.
• Regular Organ Shatter can be used instead, if Heavy Attack Windup is tolerable without.
• Rank 2 Corrupt Charge can optionally be used to save Forma. This provides the same damage multiplier on Heavy Attack at 1 less Drain, but slightly increases combo recharge time when Zenurik's Inner Focus is activated.

The Quassus also uses this build, but Primed Reach should be replaced with other mods.

Flexible Mods:
There are no free slots on the full build, but if a slot is freed up the following mods are options:

• Gladiator Might
• Dispatch Overdrive
• Additional attack speed or range.
• Rivens.