I'll change my opening unit to something, probably the XM-10 Flint, a limited production Crossbone downgrade, no problem I guess. I would, however, like to argue that the Phantom doesn't really need beamspam or funnels to be an endgame unit and that an elite PC pilot should be able to use it to keep up with, if not overcome, the typical overplayed endgame stuff. I'll list the reasons why below, just so we're clear and I don't get shafted later on because I have a supposedly underpowered unit. Also, if I make the unit sound ridiculous, just remember: the base V2 is superior in basically every way and has upgrades to boot.

So, the Phantom Gundam: It's a late UC unit equipped with wings of light. Even if its wings are a prototype with half of the V2's power that means absurd levels of speed and mobility. It's fast for an era where being fast was the MS design philosophy. A ship with a minovsky drive system like the one used to create the wings of light can travel between Earth and Jupiter in a few weeks, it takes regular ships months to do the same. The Phantom should easily outrun and outmaneuver everything in the PC camp with only the Destiny or trans-am 00 units being comparable, and then the Destiny is arguable since the smaller late-UC mobile suits were designed to be faster than their larger counterparts to begin with. The UC wings of light can also be employed offensively and defensively, acting as high output giant beam sabers/shields.

For weapons, other than the UC wings of light of course, it has two supercharged beam swords capable of cutting right through beam shields, which means trying to parry em with another beam saber save for, say, the Epyon's isn't going to help much, their output is that high. It also carries a pair of butterfly busters, which are double barreled beam weapons capable of switching into a beam saber mode. The Phantom can also generate its own i-field barrier which can be used to deflect VSBR shots. Not easily, mind, it takes obvious effort and doesn't really nullify it as much as it spreads it around in a bunch of lesser beams. But that still means it can create a strong enough barrier to repel a weapon designed specifically to punch through barriers.

If all that wasn't high tier enough for you, it comes equipped with a bio-computer system, which relays data directly to the pilot in the form of sensory information, so what the machine "feels" can also be experienced by the human operator. While the system is obviously superior with a newtype at the helm, even an oldtype can use it to increase their battle awareness and reaction times much like a newtype employing a regular psycommu system. So, to sum up, you get an absurdly fast machine with a decent if basic ranged option, good defenses, a pair of beamsabers that cut through stuff designed to repel beam sabers and wings of energy it can use to cut things apart as it zooms by, coupled with a pseudo-psycommu system that can even be used by oldtypes to compliment their piloting skills. 

And this is still inferior to the V2, which should probably be banned. Late UC is pretty insane. I'm picking the Phantom specifically because it amounts to a failed prototype of the V2 that looks about 20 times cooler and has a melee focus to boot. [url=http://img2.wikia.nocookie.net/__cb20131208133134/gundam/images/f/fa/1aa.jpg]Seriously it's a Crossbone-Record Breaker fusion that sprouts flames all over for its wings of light, has crazy beam swords that look like flames and has an F91-style face open cooling system[/url]. It's really cool and I'm pretty sure it can keep up with endgame machines without resorting to standard Gundam engame tactics. I can provide manga captures that show off its beamsabers, wings of light and other functions if you'd like, they're not available in gundamwikia or mahq. I can also list the reasons why a Flint should be about even with the given starting gundams if you'd like.