(This is part of the reason why incidental lifegain like The Celestus and Lightning Helix is important to the deck.) If we are at a lower life total than our opponent is, we can use Gideon's Sacrifice to complete the combo kill
Queza, Augur of Agonies often sees at least some wheels in its lists, but you could run it like a group hug commander with Howling Mine effects
Ace, the Fire Fist and brother of Luffy, is depicted in all his fiery glory on this card (V.2) OP07-119
Otherwise youll just have to hope your opponent is playing red
Since youre playing tri-color, Painful Truths can net you 3 cards for only 3 life
The cards are too expensive for Wizards to put them in a Commander precon, but they'll likely want to increase supply before Lost Caverns of Ixalan releases, which makes Commander Masters a pretty obviously landing spot