Valduk has at least five Auras and/or Equipments attached to it.
Steps
At the beginning of your combat phase,
Valduk triggers, creating at least five 3/1 Elemental creature tokens with trample and haste.
Activate
Phyrexian Altar five times by sacrificing five Elementals, adding ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) .
Activate
Najeela by paying ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) , untapping all attacking creatures, giving them trample, lifelink and haste, and gaining an additional combat phase after this one.
Repeat.
If
Valduk has at least six Auras and/or Equipments attached to it and/or if
Najeela attacks, this combo nets infinite creature tokens and colored mana.