At a six ink cost, its one of the riskiest listed here, but played wisely, will yield great results.
Sapphire Ink Sapphire Ink cards are full of academics that can offer a unique perspective on things
(The turn you must wait to use a freshly-played character while they dry is also a much cuter image than Magics summoning sickness.) Being able to add a facedown card from your hand to your inkwell immediately overcomes the common MTG and Pokmon bugbear of finding yourself with no land or energy cards - any Lorcana card with the ink marker around its cost can be turned into ink - and sparks a delicious dilemma about which cards to sacrifice to the inkwell in order to play others
Bouncing a creature is another tactic of Blue since it cant straight up blow up creatures like Red or Black can
But for only 1 mana, that card is going to be the best, highest quality card your deck has to offer, possibly netting you a lot of card advantage through a board wipe, stopping someone else from doing the same to you with a counterspell, or setting you up to complete an infinite combo
