No not a negative #... You can either use a multiplier [Setting] and or the dmg[Setting] its self
"skill2_setting" "es_xsetinfo wcs_multiplier 1.3|es_xsetinfo wcs_multiplier 1.6|es_xsetinfo wcs_multiplier 1.9|es_xsetinfo wcs_multiplier 2.1|es_xsetinfo wcs_multiplier 2.4"
"racealias_rai1" "es es_xsetinfo wcs_dmg event_var(dmg_health);es_xmath wcs_dmg float;es es_xmath wcs_dmg * server_var(wcs_multiplier);es est_RoundDecimal wcs_dmg server_var(wcs_dmg) 0;es wcs_dealdamage event_var(attacker) event_var(userid) server_var(wcs_dmg);wcs_getlanguage wcs_lng wcs_lng_damage;esnq est_csay event_var(attacker) + server_var(wcs_dmg) server_var(wcs_lng);esnq est_csay event_var(userid) + server_var(wcs_dmg) server_var(wcs_lng)"
"skill2_cmd" "es es_xif (server_var(wcs_dice) <= 15) then est_IsAlive wcs_alive event_var(userid);es es_xif (server_var(wcs_dice) <= 15) then es_xif (server_var(wcs_alive) = 1) then racealias_rai1"
"skill2_sfx" "es es_xif (server_var(wcs_dice) <= 15) then es_xgetplayerlocation wcs_x1 wcs_y1 wcs_z1 event_var(attacker);es es_xif (server_var(wcs_dice) <= 15) then es_xgetplayerlocation wcs_x2 wcs_y2 wcs_z2 event_var(userid);es es_xif (server_var(wcs_dice) <= 15) then es_xif (server_var(wcs_alive) = 1) then est_Effect 3 #a 0 sprites/lgtning.vmt server_var(wcs_x1) server_var(wcs_y1) server_var(wcs_z1) server_var(wcs_x2) server_var(wcs_y2) server_var(wcs_z2) 2 13 16 100 155 255 255"
Multiplier
"skill2_setting" "es_xrand wcs_rand 1 5;es_xrand wcs_damage 7 10|es_xrand wcs_rand 1 4;es_xrand wcs_damage 9 11|es_xrand wcs_rand 1 3;es_xrand wcs_damage 10 13|es_xrand wcs_rand 1 2;es_xrand wcs_damage 12 14|es_xrand wcs_rand 1 1;es_xrand wcs_damage 15 18|es_xrand wcs_rand 1 1;es_xrand wcs_damage 17 20|es_xrand wcs_rand 1 1;es_xrand wcs_damage 19 22|es_xrand wcs_rand 1 1;es_xrand wcs_damage 20 23"
"racealias_nib1" "es wcs_dealdamage event_var(attacker) event_var(userid) server_var(wcs_damage);es est_csay event_var(attacker) server_var(wcs_damage);es est_csay event_var(userid) server_var(wcs_damage) additional damage"
"skill2_cmd" "es est_playplayer event_var(userid) ambient\explosions\explode_9.wav;es es_xif (server_var(wcs_rand) = 1) then est_isalive wcs_alive event_var(userid);es es_xif (server_var(wcs_rand) = 1) then es_xif (server_var(wcs_alive) = 1) then racealias_nib"
"skill2_sfx" "es es_xgetplayerlocation wcs_x1 wcs_y1 wcs_z1 event_var(userid);es est_effect 10 #a 0 sprites/scanner.vmt server_var(wcs_x1) server_var(wcs_y1) server_var(wcs_z1) 50 350 2 90 200 0 155 155 155 155 2"
DMG its self