I don’t think this is correct. When Freddy originally became CM Jr Shazam said that CM would “share” his powers but there was never to my knowledge any reduction in Cap’s powers as a result.
Mary calls on a different pantheon so technically she wouldn’t be using a shared power source regardless. Same goes for Hoppy the Marvel Bunny.
During Jerry Ordway’s run in the 90s, there was indeed a reduction in Cap’s powers. I thought this was an interesting twist.
Of course, now Billy’s the Wizard (and no doubt has MORE than enough power to ace Clark), Freddy’s going to be the new agent of the Wizard (poor schmuck…he’s getting his power by saying Shazam! now, and Billy’s saying he’ll be CALLED Shazam…I don’t think Billy likes him too much, really. ‘Say your name! Wait, you can’t? HAHAHAAAA!’), and who knows what Mary’s status will be once she’s out of the coma she’s in.
Please spoil me. How did Mary get put into a coma?
Since we’re sort of talking about Kingdom Come, why was Billy so feared? The other two Marvels existed Elvis and Mary (Elvis was grown up Captain Marvel, Jr.) Surely these other Captains Marvel could have been a match for Superman (or those two could have matched up against Billy).
DC’s universe has entered a new era of magic. During the transition Mary and Freddy lost their powers while fighting demons. In Mary’s case she was in mid-flight. Freddy is on quest to get his powers back. So far he’s got Solomon’s wisdom again. They seem to define wisdom as knowledge of magic, which isn’t out-of-line with how Solomon has been portrayed, especially in Islamic tales. However, this is the first time that Solomon has been portrayed as a god as far as I know.
It’s a reasonable enough conceit to explain why a Jewish king is in the same club as Zeus and Hercules.
Oh, to give more detail on the Shazam Spasm, the Wizard Shazam was slain by the Spectre. Billy, now albino and calling himself “Marvel” has taken his place in the Rock of Eternity.
Well, you know, he’s probably used to it, since his name used to be “Captain Marvel Jr” and his power word was “Captain Marvel”.
“Jingle bells, Batman smells
Robin laid an egg
The batmobile lost a wheel
and the Joker ran away!”
Thank You, one and all. 
That was kind of the point of my joke, actually. <_<
Billy gives him powers by saying ‘Captain Marvel’, then he ends up named Captain Marvel jr.
Then Billy lets him have Shazam as his power word, and gives him the name Shazam.
I can just imagine the thoughts going through Freddy’s head after he says ‘Shazam’ that first time. ‘Whoo! I have the same power word as Billy and Mary, now! I can say my own name!’
‘Hello, Freddy. You will be the hero Shazam from now on.’
‘WTF? Screw you, Billy Batson, screw you!’
Oh, sorry, didn’t realize it was supposed to be a joke.
And just imagine how awful it must be for Freddy when he’s getting boned by CM and the Big Red Cheese starts in with the “say my name!” stuff.
Woo hoo, another Starman reader!
I’m getting an ugly mental picture of Superman punching a little boy in the mouth.
Grown-up Billy Batson. Fully adult in body, if brainwashed and kept mentally and emotionally about 8 years old by Luthor.
“Well that’s what I heard.” - Flash, JLU