Najeela, the Blade-Blossom | Sword of Feast and Famine

Cards

Sword of Feast and Famine attached to
Najeela.
Najeela does not have summoning sickness.
An opponent is unable to block and kill
Najeela.
Lands you control can tap to produce at least ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) .

Declare
Najeela as an attacker, attacking an opponent unable to block and kill it.
Najeela triggers, creating a 1/1 Warrior creature token that is tapped and attacking.
Deal combat damage with
Najeela.
Sword of Feast and Famine triggers, causing the defending player to discard a card and you to untap all lands you control.
Activate all lands you control by tapping them, 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 each combat phase.