Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Andrios, Roaming Explorer

Reach
As long as Andrios is attacking, tapped creatures you control with base power and toughness 4/3 have base power and toughness 16/9.
{T}: Add {W}{U}{B}{R}{G}. Creature spells you spend this mana to cast have their base power and toughness become 4/3.

The Millennium Calendar

Whenever you untap one or more permanents during your untap step, put that many time counters on The Millennium Calendar.
{2}, {T}: Double the number of time counters on The Millennium Calendar.
When there are 1,000 or more time counters on The Millennium Calendar, sacrifice it and each opponent loses 1,000 life.