Mulligans
General Mulligans
The banshee and shadow are the ones you want to ressurect the most, i make it a shadow deck to kill one myself when i have the opportunity and if the situation calls for it and just that little bit of extra damage. Undying allies makes for easy reborn, Basaleph will ressurect all minions that died. That makes 2 for every reborn minion. Easy board fill and if the enemy clears it, itll add to your xyrellas ammo.
Basically, use your banshee and shadow, keep ressurecting them with reborn and spells as much as possible, with invincible as another good one to use as much as possible. Then use xyrella and watch the deathrattle cutscene