Having both Flash and Flashback, it is a key piece in many control decks
It comes in at only 1 mana, which is honestly a breath of fresh air compared to previous cards
It also had the advantage of being more elegant than its mirror card Undermine, as it was a simple combination of Healing Salve and Counterspell for the combined price of both of them, and while the strength of the colors meant the ranking here goes the other way, Absorb shows how it's more important to get what you need rather than what is technically more valuable
Youll be able to easily sneak an attacker past blockers, and thanks to vigilance, youll also have a blocker with protection when your opponent attacks you back
If you play a lot of life gain, low mana value creatures, and/or instant speed spells, however, this card is capable of doing a lot of work