The problem with animosity is the way it works. It was set-up with a simple effect in mind that works when used on an AI but doesnt when used on another human opponent. Currently it changes changes enemy units targets to the Radiance, but another command to those units simply cancels the effect. What needs to happen is that units that are effected lose their ability to target anything but the radiance. They can still be moved, but are unable to attack anything but the Radiance itself. Much like how assault cruisers cannot target anything but structures. That way a human opponent cannot simply issue an attack order to cancel out the effect. They'll have to either attack the radiance, run away, or sit and wait until the effect wears off.
Its not useless because people FF anyway. If its the most dangerous single target your opponent is faced with, then yes it has little use, but if your opponent start ff anything else, it is useful through 1) taking a large chunk of the enemy fleets DPS off what they want to fire at and putting it on something else and 2) dividing the DPS amongst more ships, allowing restorative abilities to better combat the damage (much like shield projections help).
The idea behind animosity is how it can be used with other effects. Ideally you would use it in conjunction with vengeance from the rapture and malice and shield restore from a progen, as well as perseverance from a subjugator. In this way the opposing forces would be taking large amounts of damage from vengeance as well as it being propagated through malice for an even greater effect, and you don't even have to shoot at them. I can think of some other applications for animosity, mainly taking pressure off of other ships and structures that you'd rather save. I can see it working very well to save another cap ship from destruction giving time to escape, or taking fire from flaks or lfs to save strike craft and drone hosts. If it functioned properly it could be versatile, not the best ability ever, but certainly one that could be useful. With other caps with it, its less likely that the Radiance will be the first targeted ship in a battle. Im sure someone would find a Halcyon or a Progen much higher priority because of the power of their abilities, at which point a properly functioning Animosity would work well and could potentially save those ships.
Unfortunately I don't see IC re-working the ability to function well within the multiplayer realm, but who knows maybe they will. Changing what it does seems like just as much of a stretch as making it workable in MP, but again we'll have to see. I personally would rather have them fix it than change it.
The thing I really don't like is the ship is geared for fighting Advent only pretty much! Soaks up energy damage shore, that helps with the Viscari but it does nothign for TEC lol, actually a bad thing even.
TEC support cruisers, light frigates, scouts and capital ships use lasers which are considered energy weapons (im pretty sure). The ability you're talking about has the effect to transfer some of the damage taken by those weapons into AM, but the ability also increases the armor on the radiance, which is a good thing no matter what race you're fighting. Radiance also sports the best AM draining, ability interrupting power in the game, incredibly useful when facing powerful enemy capital ships (look out marzas). Cleansing brilliance (its lvl6) takes quite a bit of micro, but can deal ghastly amounts of damage when fired correctly and used in conjunction with the progenitors malice ability (I vaporized 25 fully upped kodiaks once, and it only took 8 seconds!)