The Masquerade (EDH / Commander)

Estrid may have a ton of masks, but the one that suits her best is undoubtedly The Chain Veil!

This is a combo deck based on Helix Pinnacle as a win condition. It requires a little bit of preparation, since you need to have an enchanted Chain Veil and a few Land Auras that, when tapped, give you at least 5 mana (of any colour, so it would work with an enchanted Sol Ring as well).
When you're all set, drop Helix Pinnacle and Estrid, and embark on an infinite combo (tap your enchanted Lands, activate the Veil, +2 Estrid to untap your Lands and the Veil, activate it again, untap your Lands and the Veil, and do it all again), giving you infinite mana and infinite Planeswalker abilities (useful if you are missing Helix Pinnacle but have another Planeswalker that can draw cards). Dump all your mana into Helix Pinnacle and wait for the win... on your next turn, if the card is left untouched (spoiler: it probably won't be) and you are still alive.
That's why Leyline of Anticipation and Teferi, Temporal Archmage are here: ideally, you want to pull off during the End Step right before your turn, and in doing so win immediately unless something goes wrong!
Ramp, draw, build your pillowfort, make tokens, protect yourself with CSs, get stuff back from the Graveyard if need be, and if everything fails, drop Starfield of Nyx and swing with your board full of Enchantments!