Sheltering Word
Two mana to make a creature untouchable for a turn and bank its toughness as life: the hexproof half is the load-bearing piece, an instant-speed shield that slips a key creature out of a removal spell's window or fizzles a targeted aura at the moment of resolution. The lifegain rides along, scaled to whatever you point it at, which quietly rewards the green decks already invested in oversized bodies: a creature with a six or seven in its bottom-right corner turns this into a sizable swing in addition to its primary job. The boundary is the one every targeted-protection trick shares: hexproof answers spells and abilities, so it does nothing against board wipes, edicts, or any effect that does not single your creature out, and it cannot pull a blocker back from a trade or save a creature from combat damage at all. It is reactive insurance, not initiative. What separates it from a pure protection spell like Vines of Vastwood is the rider: even on a turn where the hexproof goes unused, gaining a chunk of life is rarely a dead outcome, so the card carries a floor that single-purpose protection lacks, and it leans hardest in decks where the creatures it protects are large enough to make the life total swing matter.

