p. 102 Storm
Type: P • Action: Complex • Range: Special • Duration: Special
A spirit with this power can send a massive and destructive elemental storm against an area. Icy rain, bolts of lightning, hurricane force winds, and worse strike the area with reckless abandon. The affected area’s radius equals the spirit’s Magic x 100 meters. The spirit makes a single Magic + Unarmed Combat Test, and
all creatures and objects in the area are subject to Suppressive Fire (see p. 144, SR4). The Storm’s base Damage Value is the spirit’s Force and it inflicts Physical damage.

Type:M • Action:Complex • Range:Touch or LOS • Duration:Permanent
The Energy Drain power is used by a number of dangerous
critters and spirits in different ways. Each version of this
power is slightly different, depending on the entity using it. All
versions entail the creature using this power to suck life energy
from a victim, in the form of Karma, Force, Magic, or Essence.
The Essence Drain used by vampires (p. 288, SR4) is a variant
of this power. For some creatures (blood spirits, shedim,
mantid spirits), this power is Touch range, meaning a resisting
victim must somehow be subdued first or drained unwittingly
(as FAB does). For other beings (shadow spirits), this power
merely requires line of sight, allowing the critter to feed off its
victims from afar.
Draining a point of Karma, Force, Magic, or Essence requires
a Willpower + Magic (10 – target’s Essence/Force,
1 minute) Extended Test (for some critters, the interval may
differ, as specifically noted). If the critter is disturbed or interrupted
before this test ends, the point is not drained. If the
Extended Test is completed, the critter drains one point of the
specified energy, adding to its own. (In some cases, the energy is
converted to an appropriate rating point at a 1:1 ratio, as noted;
for example, blood spirits convert drained Essence to Force.)
Some critters (FAB, mantid spirits), used the drained energy to
reproduce, as noted in their individual descriptions. Drained
points are permanently lost.
Living victims find this process draining at best, extremely
painful at worst. Victims suffer 1 box of damage for each point
drained. Depending on the critter, this may be Stun damage
(shadow spirits, FAB) or Physical damage (blood spirits, shedim).
Victims who take Physical damage appear drained, withered, and
hollow, and are sometimes marked permanently (white hair, hair
loss, wrinkles, premature aging, or other strange markings).
If a character’s Magic is reduced to 0, he burns out and becomes
mundane. If a critter’s Magic is reduced to 0, it dies. If a
spirit, sustained/anchored/quickened spell, focus, or mana barrier’s
Force is reduced to 0, it is destroyed. If a victim’s Essence is
reduced to 0, he dies.

p. 100 Energy Drain
The fourth line of the third paragraph should read:
“In some cases the energy is converted to an attribute modifier at a 1:1 ratio; for example, blood spirits convert
drained Essence to a Force modifier.”
p. 100 Energy Drain
At the end of the second paragraph add the following line: “Attribute modifiers granted by Energy Drain are limited to 1.5 times the draining entity’s Magic rating (in the case of spirits, their Force when initially summoned.)”

Through the Force 5 Sustaining Focus.
Increase Willpower Force 5 Magic 6 + Spellcasting 6 (+2 Health) ([1,5,2,2,6,1,6,2,3,5,5,3,6,3]) 6 hits, 1 is discarded, that's enough for Force 5. So he now has +5 Willpower which is reduced to just +4 since the max is 9.

This +4 bonus is not applied to this spell's drain at least.

Drain is F/2 - 2, reduced to 1. Drain of Force 5 Increase Reflexes is (F/2)-2, reduced to 1. (10d6.hits(5)=5)

Summoning Force 5 Spirit of Man with Slaughter Infected. Force 5 Spirit of Man: Magic 6 + Summoning 2 (+2 SoM) (10d6.hits(5)=3)
Opposed test vs Force 5 SoM: Force 5 Spirit of Man (5d6.hits(5)=1)
So 2 net hits. First service owed is Concealment of all of us, and we can see each other, and concealed also on the Astral.
Drain is twice of the Spirit's hits, so 2. Summon Drain (Force 5 had 1 hit, DV 2) (14d6.hits(5)=6) No Drain.

Oh I forgot to apply the Centering mod which is +4 to the Drain pool. Will do so now, though it hasn't been necessary. Drain dice is 14 +4 from Centering.

Finally, casting an Empty Trid Phantasm centred just in front of Brox's chest.

Force 5 Trid Phantasm: Force 5 Trid Phantasm: Magic 6 + Spellcasting 6 (12d6.hits(5)=6) 6 hits, reduced to 5.
Drain (F/2) + 3, DV5: Force 5 Trid Phantasm Drain Resistance: Int 5 + Will 5 (9) + Centering 4 = 18 (18d6.hits(5)=7) No drain.

Extended Masking makes Brox's aura as a ghoul's, and his two quickened spells, one focus, and one sustained spell as part of his own aura.

His centering method by the way is breathing in deeply then slowly exhaling while concentrating on the spell. He's almost whistling.