Opponents have a collective life total of 150 or less, or your deck size is equal to or greater than 5 times the number of Demons you control and your life total is equal to or greater than that number plus one.
Activate Orthion's second ability by paying ({6} magic symbol) ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) and tapping it, creating five token copies of Be'lakor.
Put all the Be'lakor tokens into your graveyard due to the legend rule.
Each Be'lakor token's first ability triggers, the nontoken Be'lakor's second ability triggers five times, and each Be'lakor token's second ability triggers four times.
Resolve the nontoken Be'lakor triggers, dealing 30 damage to up to 5 targets.
Resolve all the Be'lakor tokens' second abilities, dealing 120 damage to up to 20 targets.
If needed, resolve all the Be'lakor tokens' first abilities, causing you to draw five cards for each Demon you control and lose that much life.