Opponents can not block and kill creatures you control.
({R} magic symbol) ({W} magic symbol) available.
Steps
Activate Slayers' Stronghold's second ability by paying ({R} magic symbol) ({W} magic symbol) and tapping it, giving Jegantha +2/+0, vigilance, and haste 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.