Neheb, Imminent Doombringer

Whenever you cast a spell with converted mana
cost equals to one plus the number of doom
counters on Neheb, Imminent Doombringer,
put a doom counter on Neheb.
Remove a doom counter from Neheb, Imminent
Doombringer: Add {r}, then Neheb deals 1
damage to any target for each doom counter on it.