The Stealth Rhienn is the first refit available to a Romulan player. It doesn’t have any research requirements, so if you want to start building your fleet with these sophisticated vessels, there’s nothing stopping you.
The Stealth Rhienn - like all Rhienns - is an Offensive vessel. It is equipped with pulse weaponry and a full arc disruptor. This allows the Stealth Rhienn to be a decent raider and gives it some kiting capabilities. Like the other Rhienns, it has a Doctrine as well. This Ambush Doctrine allows it to deal extra pulse damage when near a friendly Mine. This obviously makes the Stealth Rhienn quite effective at performing ambushes and gives it a special relationship with the Generix Minelayer.
The Stealth Rhienn also carries a unique special technology: Plasma Flares. Plasma Flares cloak the Stealth Rhienn upon activation, and also cause iit to be lost as a target upon activation. Likewise, two small plasma flares are left behind, which attract enemy fire with their extremely energetic signatures. While flares only last for a few seconds, they will attract all enemy fire. This not only allows the Stealth Rhienn to usually survive combat, but also gives it the chance to provide limited cover fire for your nearby vessels!
However, the most special aspect of the Stealth Rhienn, and the thing that makes it a true STEALTH unit, is its Aldovh cloaking device. This highly refined technology is only available to a few of the Star Empire’s vessels. The Aldovh Cloak allows it to pass through Tachyon detection unmolested. This may not seem like much, but that’s because we haven’t yet discussed cloak detection in Version 4.
In Version 4, each faction yet again has different methods to detect cloaked vessels. However, while most 327 cloak detection included Graviton Pings - which could detect basic and advanced cloaking systems - Version 4 cloak detection is layered. We want to promote the idea of a true cat and mouse game between a cloaker and the non-cloaker, where both players should feel comfortable advancing their cloak and counter-cloak technologies.
Let’s briefly go over the Federation cloak detection system.
Federation cloak detect is no longer researched at Starfleet Science - turns out all those guys at Outpost-control really had nothing better to do than drink coffee, and thus were given some extra research assignments. Yay research! While researching cloak detect at the Outpost isn’t all that expensive, it does take a lot of time to complete. There are 4 researches, and each one takes a minute longer than the last one - it thus takes you 10 minutes of full research time to get out your über cloak detection. Lots of research time means lots of build time lost too. As a consequence, a Federation player must carefully balance researching cloak detection with economy building.
The first research - Tachyon Ping Upgrade - simply outfits your Sensor Platforms with a Tachyon Ping. The second research - Progressive Scan Upgrade - grants your Venture scout vessels the ability to use a Tachyon-ping equipped Progressive Scan. The third research - Virtual Triangulation Upgrade - improves the detection chance of all your Tachyon pings by 50%. The final research - Graviton Ping Upgrade - gives the Progressive Scan a Graviton-ping.
This is all pretty standard stuff, and not that different than the types of cloak detection in Version 3. However, researches 2, 3 and 4 also add an additional layer of cloak detection to the Sensor Platform not discussed in the above paragraph: so-called Deep Space Scan. This special detection grid is made possible by measuring chroniton and other radioactive emissions from regular cloaking devices. Instead of revealing a vessel outright, the imprecise nature of these Deep Space Scans gives you the ability to see where a regular cloaked ship might be while it is within the very long detection radius of the Sensor Platform. In-game this is represented by a minimap ping for each enemy cloaked vessel every 10 seconds. This ping is seen by both you and your opponent, allowing an opponent to bring Progressive Scan-equipped Ventures to reveal you, as well as warn or discourage a cloaker from attacking a location. Further researches simply improve the range of the Deep Space Scan.
So how does this relate to Aldovh cloaking devices? If you notice, not only do Deep Space Scans not detect such advanced cloaks, the only layer of the Federation cloak detection that does is the fourth research! This makes the Stealth Rhienn a perfect late game harasser, and allows you to operate behind enemy lines largely undetected to disrupt your opponent’s strategy.