The Eye of Magnus

When you tap a land for mana, that land
produces double the amount of mana as it would normally. When one or more charge counters are
put on The Eye of Magnus, each opponent
creates a colorless 1/1 Manawight token.
{2}{g},{t}: target creature you control gets +3/+3
until the end of the turn; put a charge counter on
The Eye of Magnus.
{2}{b},{ut}: Draw a card and you lose 2 life; put a
charge counter on The Eye of Magnus.