Necrosis

At-will, std, ranged; subject suffers heavy necrotic damage, as their body begins to necrose or rot (as you prefer).

At Rank 2, at-will, std, ranged, circle 1/rank; medium necrotic damage to all targets in the area, and the area becomes difficult terrain as it becomes covered in decay and filth.

At Rank 2, at-will, std, ranged; you grow a limb, mouth, or similar body part, made of dead flesh, from the body of a living or dead creature, and control the growth as you would a summoned creature. You can use these limbs to attack, grapple, or perform other actions as you direct. An arm has the same strength as its host, a mouth can cast its own spells, etc. It is a swift action to command the minion each round; without new commands, it will attempt to repeat the last command it received. The growth has HP equal to a medium damage roll; when it reaches 0, it is destroyed. All damage it suffers is also suffered by the host, and if the host dies, the growth immediately withers and dies as well.

• When casting with only a mouth or a hand, the growth must cast using the Silent Spell or Still Spell action, as appropriate. Since it only gets one action per round, it must spend an action to prepare such a spell, then cast it in the following round.
• A single limb can only attack with a natural or unarmed attack, or a one-handed weapon (if available).

At Rank 3, you can sprout two limbs, mouths, etc. This enables either dual-wielding or wielding a two-handed weapon, or casting spells without Silent/Still spell.

At Rank 3, at-will, std, target; subject suffers heavy necrotic damage, and the resultant decay bursts forth from their body, becoming a disgusting, animate undead creature under your control. It has HP equal to the damage the subject suffered, and it can use the subject's physical abilities--albeit, it is one size category smaller and its physical damage is reduced one step (heavy->medium, etc).