Tom Bombadil

As long as there are four or more lore counters among Sagas you control, Tom Bombadil has hexproof and indestructible.
Whenever the final chapter ability of a Saga you control resolves, reveal cards from the top of your library until you reveal a Saga card. Put that card onto the battlefield and the rest on the bottom of your library in a random order. This ability triggers only once each turn.

Esper Terra

(As this Saga enters and after your draw step, add a lore counter.)
I, II, III — Create a token that's a copy of target nonlegendary enchantment you control. It gains haste. If it's a Saga, put up to three lore counters on it. Sacrifice it at the beginning of your next end step.
IV — Add {W}{W}, {U}{U}, {B}{B}, {R}{R}, and {G}{G}. Exile Esper Terra, then return it to the battlefield (front face up).
Flying

Terra, Magical Adept

When Terra enters, mill five cards. Put up to one enchantment card milled this way into your hand.
Trance — {4}{R}{G}, {T}: Exile Terra, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery.

Terra, Magical Adept // Esper Terra

Case of the Shattered Pact

When this Case enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
To solve — There are five colors among permanents you control. (If unsolved, solve at the beginning of your end step.)
Solved — At the beginning of combat on your turn, target creature you control gains flying, double strike, and vigilance until end of turn.

Chamber Sentry

This creature enters with a +1/+1 counter on it for each color of mana spent to cast it.
{X}, {T}, Remove X +1/+1 counters from this creature: It deals X damage to any target.
{W}{U}{B}{R}{G}: Return this card from your graveyard to your hand.