Shadows are always slightly visible (like normal ghosts when they are moving) by default. As they start moving however, they will reach specific stages that will affect their current visibility status; as shown on their gauge:
- Stage 1: Partial invisibility; default (stationary).
- Stage 2: Invisibility; with a trail following them.
- Stage 3: Total invisibility, detectable by sounds.
As they can be totally invisible, their breath and footsteps are loud and clear in order to balance gameplay. Security devices (sensors, sprinklers, etc) in exclusive maps will also help soldiers detect them. Finally, all actions other than running will affect their status by decreasing their gauge bar either slightly or significantly.
Depending on the gender of the character that the player is using will affect the appearance of their Shadow character. The female ghost has a more visible skin with orange coloration, she has belts and knives around the waist and hips. The male ghost is completely covered unlike the female ghosts, wears a belt around the waist and his knives are strapped to his back.
- The knives that appear on the shadows are not usable and serve no purpose so far apart from being cosmetic. Shadows will only use the melee weapons in the player's bags.
- Although their knives weren't available to use initially; they were later released as a standalone melee weapons available to obtain in some versions: Shadow Knives.
- A glitch will show the Shadow's model to always run with one arm behind them, which might lead to amusing visual glitch in third person with some melee weapon (i.e Aluminum Bat).
- As stated above, because of the way a Shadow would holds its melee; it could be possible that the shadows might have different hit boxes than normal. 
In CF Vietnam, Shadow Warriors (Called Fury Ghost) are available as normal charaters with superior skills: 100% Flash Immunity, 50% Smoke Reduction and Footstep Sound, making them the best characters, even better than characters available in AI Ticket System (SBS, RedPower, Ranger, Devil Hunter Merc.) or Ngọc Trinh (in the Item Shop). This character has been added to the system for as long as the Shadow Mode was released but due to coding error, using it will result in players turning into Hero characters and caused disconnection. It's only been fixed very recently.
Since Shadow Warriors are not designed to be a normal character, there are a few quirks among them - the only two available are male and female form (based on their owner's genders), and they must wear the Double Dagger Tattoo in order to be used (Two specialized VTC accounts come equipped with this item to make sure FuryGhostM / W is functional). Unlike Nemesis that used to have the ability to change gloves skin based on equipped weapons, FuryGhostM / W is capable of changing weapon skin color herself.
Because of the OPed nature of Shadow Warriors, they are provided in very limited quantity:
There are only two Fury Ghost existed for specialized VTC accounts, that will become a gift for a charity auction during CF Vietnam's 9th Anniversary Party in Hanoi and HCM City. All of the profits earned are donated to Tran Duc Doanh, a long time CF player who lost one of his legs but continued to show passionate to this game.
The number of obtainable Fury Ghosts have been expanded to 200 to celebrate CF Vietnam's 10th Anniversary, 10 of each being given to one of the 20 cities that host the party. To balance this, Fury Ghost is now restricted to the Treasure Chest web-event - 10 lucky players will be given the chance to spin this special wheel 10 out of 12 turns and win up to 10 permanent weapons (including Noble Gold and VVIPs), and the goal is to win Fury Ghost within the first 10 spins. This ensures Fury Ghost won't be a sure-win for the selected players (Although on the first day, someone managed to win 3 Fury Ghost in-a-row, which is likely a glitch because the wheel is programmed to not give duplicated prizes).
Fury Ghost was later made available to all players for a short period of time at the end of June via the special Treasure Chest - it has been re-programmed to function like Capsule and give out prizes randomly instead of a guranteed sure win after 12 spins. Only one player managed to win the 3rd Fury Ghost via this event after spending nearly $1500 on the Chest.
Fury Ghost was also made available in a VIP Top-Up race at the start of July - only one player will be given this character for buying the most VVIP pieces during July 1st - July 10th. So far, the current record is 190 VVIP pieces (Which comes down to roughly $2000 given the cheapest price available).
As of February 2019 update in CF Vietnam, the Fury Ghost have been crippled with glitches that renders their special abilities useless, even more so it can't be fixed with Flashbang / Smoke reduction items. In addition, Fury Ghost users will randomly be kicked out of the room due to 29_1 error when getting hit with Flashbang from other players, and if this error is encountered repeatedly, an auto ban will take place.
VTC has yet to be able to resolve this issue, and so to this end they offered to compensate Fury Ghost players with 3 years Flash/Smoke reduction items, along with one free new Black Market item every patch until the issue is resolved. This however, is not appreciated by Fury Ghost players because they've already owned items very long time due to all of the top up events, and they still couldn't get any storage expansion so they wouldn't be able to receive any new weapon anyway.