The principle behind this deck is to get a Nearheath Pilgrim onto the field.
The next step is to have a Spitemare, or more preferably, Boros Reckoner, on the field. (Arcbond, however, may also replace this part of the combo).
Additionally, this step may be skipped if necessary and instead, what you need to do, is get a hold of an Aetherflux Reservoir and pay the life cost. Finally, the trigger. The trigger for this combo is Volcano Hellion.
The trigger works by soul binding Pilgrim to Hellion for the lifelink bonus, choose a fucking absurd number for Volcano Hellion to deal.
Example:
Nearheath Pilgrim is on the field when Hellion enters. Both now have lifelink.
I choose a dodecadillion of damage to myself, and to Spitemare or Boros Reckoner or Any creature targeted with Arcbond).
Hellion deals the dodecadillion damage to me, but lifelink results in a net 0 life loss.
Now Hellion deals a dodecadillion to Pilgrim (or more preferably, Spitemare / Boros Reckoner / Any creature targeted with Arcbond).
Potential combos are:
Grace / Gideon + Hellion + Boros Reckoner / Spitemare / (any creature (including Pilgrim) after casting Arcbond) = Unlimited life + Damage
You can sometimes get away with not comboing at all, if AND ONLY IF they have less life than you. You can do this by skipping the Pilgrim part of the combo and face tanking the damage so long as they die before you. This play is definitely riskier, but it can pay off.
Beyond the combo, there's Simian Spirit Guide for that aggro casting.
For control, we have Spellskite and Grand Abolisher for spell countering.
And finally, the obligatory Lightning Bolt for plain old creature removal.
Perfect hand: Pilgrim, Reckoner, Hellion, 3xSimian, and a Pain land. (Hopefully draw some pain lands and Detonate turn 3).