Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Undaunted (This spell costs {1} less to cast for each opponent.)
Destroy two target creatures.

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Exile target creature. Its controller gains life equal to its power.

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.