Activate Yenna by paying ({2} magic symbol) and tapping it, creating a token copy of Ordeal of Nylea, then untapping Yenna and causing you to scry 2.
Activate Phantatog's first ability by sacrificing the Ordeal of Nylea token.
The Ordeal of Nylea token's second ability triggers, causing you to search your library for two basic land cards and put them onto the battlefield tapped.
When the lands enter the battlefield, Amulet of Vigor triggers twice, untapping them.
Resolve the Phantatog ability from step 2, giving it +1/+1 until end of turn.
Activate the two lands by tapping them, adding ({2} magic symbol) .
Repeat.
Results
Put all basic lands from your library onto the battlefield.