Wyll, Blade of Frontiers

If you would roll one or more dice, instead roll that many dice plus one and ignore the lowest roll.
Whenever you roll one or more dice, put a +1/+1 counter on Wyll.
Choose a Background (You can have a Background as a second commander.)

Brazen Dwarf

Whenever you roll one or more dice, this creature deals 1 damage to each opponent.

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."

The Space Family Goblinson

The Space Family Goblinson has trample as long as you've rolled three or more dice this turn.
Whenever you roll a die, put a +1/+1 counter on The Space Family Goblinson.