Cast Wingmantle Chaplain by paying {3}{W}.
Wingmantle Chaplain's ETB ability and Dormant Sliver each trigger.
Resolve Dormant Sliver's trigger, drawing a card.
Resolve Wingmantle Chaplain's trigger, creating a 1/1 Sliver token with defender for each creature with defender you control.
Wingmantle Chaplain's last ability and Dormant Sliver each trigger once for each token created; put them on the stack in any order.
Resolve a Dormant Sliver trigger, drawing a card.
Resolve a Wingmantle Chaplain trigger, creating a 1/1 Sliver token with defender.
Repeat steps 5 through 7 until there are no cards in your library.
Put Wingmantle Chaplain's and Dormant Sliver's triggers on the stack in any order.
In response, cast Savage Summoning by paying {G}.
Cast Thassa's Oracle by paying {U}{U}.
Thassa's Oracle enters the battlefield and triggers.

Infinite card draw

Infinite creature tokens

Infinite creature ETB

Win the game

Dormant Sliver

Wingmantle Chaplain

Maskwood Nexus

Savage Summoning

Thassa's Oracle

Hivestone

Combos with "Savage Summoning"