Aurelion Sol, Starforger

Indestructible, flying
If you tap a permanent for mana
to target an opponent with a spell or an
ability, it produces twice as much of that mana.
Whenever this creature deals combat damage to
a player, exile the top card of that player's library.
If it's a nonland card, you may cast it without
paying its mana cost.
"Cower, worship, beg, they're all valid reactions."