Opponents can not block and kill creatures you control.
Steps
Play Sandstone Bridge.
When Sandstone Bridge enters the battlefield, it triggers, giving Jegantha +1/+1 and vigilance until end of turn.
Move to your combat phase, and declare Najeela and Jegantha as attackers.
Najeela triggers, creating a 1/1 Warrior creature token that is tapped and attacking.
Activate Jegantha 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.