Before I make any arguments regarding anything else, my query remains unanswered. The Silent Orb's size in relation to the Silent Core. The Silent Orb had just been created, which means that the size it was portrayed at was its base. Just like similar triangles, where every side and the area is determined by proportions, I'd like to believe that the Silent Orb functions under similar mechanics, as it is identical in every way except size to the Silent Core. The Silent Orb is at least 1 foot wide (not 1 metre as previously mentioned), and the Silent Core would be at least 30 feet wide via keeping Naga within it. I'm not able to pixel scale, so I'll try to find a picture of the Silent Core next to something we can scale from. I know the wiki doesn't function under assumptions, but this is probably my best bet on placing a baseline power level for any Bakugan that scales to the Silent Orb:
Silent Orb's volume: approx. 0.52 cubic feet
Silent Core's volume: approx. 14,137 cubic feet
Number of times Silent Orb would fit in Silent Core: 27186.53 times.
How much power would the Silent Orb possess: 1/27186.53 of the power in the Silent Core. Silent Core grants a 3-A level of power, so this at the very minimum would likely be 3-C
I know this won't be accepted, but I tried.
NOW, real arguments:
Perfect Drago was explicitly stated to be the one keeping all of Vestroia together, therefore I'd presume he's also managing the space-time of the specified universe. 2-C, but stating that he's at least 3-A is on the safer side.
The Legendary Soldiers are nowhere near Tier 3 from what I know of the series. They were probably fighting against the Battle Brawlers under heavy PIS. In New Vestroia, the Legendary Soldiers combined were unable to face Assail FARBROS (King Zenoheld's Bakugan) and were utterly defeated while fighting at full power, FARBROS should be superior to Helios MK2 as the strongest of the Vexos Bakugan, placing him at 5-B at the very least. The Legendary Soldiers are only watching over the Perfect Core for imbalances and to inform Drago of problems. Exedra, the Darkus Guardian, is also stated by the narrative as possessing the most power of all the Guardians, and Apollonir is only the leader because of skills.
Neo Dragonoid is more powerful than Delta, right? After being captured by Spectra, some Forbidden Ability cards were used upon him. This allowed him to use some of the Perfect Core's power unhindered. Apollonir is then used by Dan to battle this "Vexos" Dragonoid. By turning into lance form, Dan then throws him into the diamond on Drago's chest, which is his permanent link to the Perfect Core, where Apollonir absorbs the excess energy, Note that the battle had already been going on for quite some time. What prevented Spectra, using the strongest Bakugan of all at that point in time, from beating Apollonir? Apollonir was defeated by Delta Dragonoid. Both these situations are extreme PIS.
Now here come the wild inconsistencies. The Alternative Weapon System was introduced in New Vestroia. Spectra, whom I would consider a reliable source of such statements, identifies the AWS as a creation capable of wiping out entire galaxies along with its living beings, which would mean a tier of 3-C. (right here:[http://
https://youtu.be/H7g59YD8b6k?t=19m38s https://youtu.be/H7g59YD8b6k?t=19m38s] ). This would also mean it needs to possess a durability somewhere near that level to fire off such attacks as it is not made of organic material. At the very least one of its attacks from a large cannon (it has multiple) should be planet level, as the AWS was going to destroy Earth and Vestal. From here we can justify a 5-B tier for Helix Dragonoid, as at
this point Drago fires off an attack known as Galactic Dragon which effortlessly counters a beam from the large cannon, removing his unknown tier, for his full power form. Of note is the fact that Saint Nemus, had just used an ability to rejuvenate all the Bakugan present, or even amped their stats.
In the 2 final episodes of the Battle Brawlers vs the AWS, Helios MKII has a Zukanator strapped to his back, which is just a massive cannon that fires pure energy, when it out of nowhere just blasts a hole through the AWS, while all the Bakugan Brawlers have also been destroying various other parts of it. The Bakugan anime probably has the greatest amount of PIS I've ever seen. The jump from 5-B to 3-C is
massive and even that's an understatement.
So,
Perfect Drago: At least 3-A, possibly 2-C
Helix Drago: At least 5-B
Legendary Soldiers: Possibly 5-B