Killer Eagle
From Random Booster 10, one of three prize Beyblades alongside Rushing Boar and Death Gargoyle, the three came in Red, Blue and Green, with Blue being the prize colour for this Beyblade.
Picture provided by @Beyfinity
Weight: 5.1g
Five-sided AR with relatively aggressive design, slopes facing each direction.
Notable for being the only AR that lines up with Star Attack in any reasonable way.
Right Spin:
Lack of range, obstruction and inward angle of contact points results in unimpressive Smash Attack
Too much recoil for Defensive or Stamina use
Penta Wing's Upper Attack in this direction is largely limited to destabilization, thus not worth using.
Left Spin:
Solid Upper Attack in this direction due to the reasonably long slopes on each wing.
Moderate but not excessive recoil.
These attributes make Penta Wing a viable, if very offense-focussed Attack Ring for Spin-Stealing Attack. Its recoil does cause it to lose match-ups, particularly same-spin, where Upper Dragoon might win by outspin, but the increased offensive ability makes it reliable in other match ups.
Slopes make it effective as a Left Spin Traditional Upper Attack AR, and it is a very compelling choice for this - which also makes Star Attack a viable competitive part just for this reason.
Overall while there are many alternatives, Penta Wing is quite unique and effective.
Weight Disk: Random
Possible Weight Disks are: Star Attack, Revolver Attack, Ten Heavy, Ten Balance and Ten Wide.
Spin Gear: Neo Right Spin Gear (Metal Weight Version)
Weight: 1.15g ea (total 2.3g)
Generally preferred to regular Right shells due to being compatible with all SG-Compatible bases, in particular for being compatible with Neo SG Cores and the Heavy Metal Core.
This means they are a necessity for Compacts, Weight Based Defense, Force Smash, Traditional Upper Attack and Driger V2 Combinations, at least aside from the rare occasions Left Spin is desired for one of these types, in which case Neo Left Shells are preferred.
Overall a crucial competitive part, but thankfully exceedingly common.
Weight: 2.5g
Only compatible with Neo Shells.
Has a cylindrical metal part in the centre to add weight
Slightly lighter than Magnecores, which limits its usefulness, even for Attack Types where the small difference between it and other cores in terms of weight means it generally fails to find a niche, or at least fails to stand out as significantly better in most cases.
This does not mean it is outclassed for all setups, however, odds are it provides the right mix of recoil control and speed for some setups, it is just that the difference it would be best by would inevitably be quite small.
Does still work well for Attack Types in general, despite usually being outperformed by other options the difference is quite minimal.
It is possible to get alternate Blade Bases with Random Booster beys, especially with non-prize Beyblades. In Killer Eagle's case, the most common alternates are SG Flat Base and SG Sharp Base.
Weight: 4.7g
SG version of Semi-Flat Base.
Tip is slightly differently angled from Semi-Flat Base, being more shallow. Wears quite quickly.
Semi flat tip is nice, being predictable and not difficult to use, but Metal Change Base has better attack, defense, and survival, while Metal Ball Base once worn has a similar but more effective tip shape due to better precession.
It is generally outperformed as a result of these factors.
In addition, Metal Ball Base with Six Metal Balls has a similarly well-behaved tip but 1g more weight.
Nonetheless, it is a competitive part for Compact Customizations as it does work well and they remain competitive using it - just perhaps slightly less capable than with alternatives.
There is a second mold which tends to be slightly heavier than the original, due to two molding cylinders. Performance is generally identical.
Overall
While it has a unique and rather effective Attack Ring in Penta Wing, Killer Eagle fails to make much impact for how rare and expensive it is. As such, while it is a nice addition to ones collection, it is by no means a must-have.