First of all, according to Diga Altman's own strength, as a Warrior of Light, he has four forms: initial form, strength form, air form and shining form. Facing different forms of strength, Glitter Tiga has always been regarded as the strongest Otto warrior. In the face of Dark Tiga's strength, the Dark Giant existed in the ultra-ancient period 30,000 years ago, and his strength is the strongest among his partners. However, as a dark giant in the Archaean period, he didn't defeat the Catantjeu who destroyed the Archaean period. In this case, I personally think that Dark Tiga's strength is not so strong.
Facing the strength of Hiro in the dark, as the only one in the new generation who didn't completely rely on the strength of other Otto fighters, his own strength in various forms was very strong, especially after being possessed by beria. Ciro could have become close friends with him, but the dark Ciro actually killed them directly. Faced with such terrible strength, it is not difficult to see the strength of Ciro itself.
Here is an example. If Dark Tiga can defeat Gatanteeu, why didn't Dark Tiga stop Gatanteeu from destroying it in the Archaean era? And the strength of Cicero, personally, I think he is fully capable of defeating it. The same enemy has two different results, which is why I think Dark Siro is powerful.