Cast Nexus of Fate by paying ({5} magic symbol) ({U} magic symbol) ({U} magic symbol) , causing you to take an extra turn after this one and shuffle Nexus of Fate into your library.
At the beginning of your combat phase, Helm of the Host triggers, creating a nonlegendary token copy of Carth with haste.
Move to your postcombat main phase.
Activate Liliana's second loyalty ability by removing zero loyalty counters from it, searching your library for Nexus of Fate, then shuffling your library and putting it on top.
Move to your next turn, drawing Nexus of Fate during your draw step.