[EnerPrime]

There's not really an explanation for why Basco's summons are weaker than the real deals, just the simple equation of 'power+proper user > power used as a bad guy's puppet'. Basco's DiendTrumpet just can't get the same amount of power out of the keys as someone actually wearing the suit.

I was always okay with the non-fighting roles of the cameos because I figured the past Sentai had to have a reason for letting the Gokaiger keep their powers instead of just asking for them back. Especially considering that repowering the past Sentai is just a matter of giving the appropriate key back. Do you really think so many past Rangers would be okay with not getting their powers back if there wasn't some advantage to Marvelous and crew having them all?