Bowser's Magic
A little fact people often forget is Bowser has the ability to wield Magic and has done so on many separate occasions.
The prime and most well known example is in Super Mario Bros. when turns all the Toads into Bricks and Horsetail plants.
In Super Mario Bros. 4: Super Mario World he uses his magic to trap Yoshi and his friends in eggs. "Mario and co. saved their friend who was trapped in an egg by Koopa's magic." "Until once again the great Demon King Koopa appears, his magic is cast on the Island's dinosaurs." From Japanese Mario World is VERY Different - Region Break He also used his magic to brainwash the Reznors.
In Super Mario RPG: Legend Of The Seven Stars Bowser gets several special moves that he can uses on his opponents. Poison Gas and Crusher are 2 of these spells.
In Super Mario 64 in Bowser's fights we will teleport around at times.
In the Yoshi Story a Baby Bowser cursed Yoshi's Island and turns it into a storybook.
In Super Mario Galaxy Bowser is spitting out meteorites and using dark matter.
In Super Mario 3D Land Bowser can literally run on air.
In the Mario Party games Bowser can either summon his minions to himself or teleport players to him. He is also able to use a wand to transform someone.
He can also use his magic to create castles and towers.
Since the Mini Koopas are clones of him, he probably can duplicate himself.
Also, not only can he become Dry Bowser but he can more easily use blue flames which characters like King Boo can use.
Finally I'd note that in games like Super Mario 64 it mentions Bowser is using the magic from the Power Stars to do what he is doing. And in games like Mario Party 9 and Super Mario Galaxy he has either a Grand Star or Mini Stars in his possession. I think that Bowser has magic default but can get access to more potent magic if he has a star or a wand in his possession.

















