Dragons of Tarkir gave us five newcomers (Dragonlord Silumgar, Dragonlord Atarka, etc.), Core Set 2019 gave us retrains of the originals (Arcades, the Strategist, Nicol Bolas, the Ravager), Strixhaven added five more as the namesakes of the different schools (Tanazir Quandrix, Beledros Witherbloom, etc.), and the five metal dragons from Baldur's Gate were also given the double creature type (Ancient Bronze Dragon, Ancient Copper Dragon, etc.)
Despite that your odds on useful turn one Mox plays are low
The fact that Spellspear transforms into an even bigger creature that has Ward 2, trample, and prowess is where things get a little out of control
Commander has accelerated enough that a two-card combo involving two six-mana creatures isn't the most threatening thing in the world, but Mikaeus is still potent as a standalone card
Early in the game, it forces opponents to pay extra mana or lose their key creature or planeswalker