Najeela, the Blade-Blossom | Jegantha, the Wellspring | Helm of the Host

Cards

At the beginning of your combat phase,
Helm of the Host triggers, creating a token copy of
Jegantha with haste that isn't legendary.
Activate the
Jegantha token by tapping it, adding ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) that cannot be spent to pay generic mana costs.
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.