Activate Phyrexian Altar by sacrificing Optimus Prime, Hero, adding one mana of any color.
When Optimus Prime, Hero dies, its second ability triggers, returning it from your graveyard to the battlefield as Optimus Prime, Autobot Leader.
Activate Phyrexian Altar by sacrificing Optimus Prime, Autobot Leader, adding one mana of any color.
When Optimus Prime, Autobot Leader dies, Mikaeus triggers, returning Optimus Prime from your graveyard to the battlefield as Optimus Prime, Hero with a +1/+1 counter on it.