Mars being in the sign of Pisces will not result as a "diluted" energy, but as a particular energy, surely different from others placements of the planet.
It certainly won't be an energy as disruptive as that of Mars in Aries, but the nature of the planet is still channeled within the circumstances governed by the sign, and other astrological energies that may interact with the planet in question, in that particular moment.
The same applies for Saturn.
The way to dilute the eventual evil energies that may result from astrological "situations" is meditation. It is important to apply the aura of protection regularly, and work on your soul in the long term.