Ace, The 16th Doctor

{3}: Roll a D6, then Time Travel {x}, where {x} is the value of the rolled D6.
{7}; Roll a D10, then destroy target creature with converted mana value less than or equal to the value of the rolled D10.
{10}Roll a D20: 1-19, nothing happens. If a 20 is rolled, gain a Luck token.
(Luck tokens allow you to re roll any dice with a favourable outcome by adding 3 after the reroll.)