GEORGE NORTH (Wales, wing)
The Northern Hemisphere's most complete wing has first found his feet, then driven his game to new heights since his summer Northampton switch.
Imperious under the high ball, an increasingly match-turning tactic, the former Scarlet is also as quick of foot as he is of wit.
Australia felt his full force in the British Lions' victorious summer tour, and now Wales' European rivals will have to find a way to stop his midfield line breaks and his sweeping wide play.
BILLY VUNIPOLA (England, number eight)
England will miss the brute force of Manu Tuilagi, the Leicester wrecking-ball who is unlikely to feature after injury.
Stuart Lancaster can still call on the Vunipola brothers of Tongan descent, but he will not be worried about lineage, more number eight Billy's ability to ravage a defensive line.
Wasps' rampaging loose forward will share duties with Gloucester's Ben Morgan.
If he starts he will be tasked with softening up opposition packs, but he could just as equally be challenged to change a game in the last 20 minutes.
WESLEY FOFANA (France, centre)
The Clermont midfielder is an outside centre in the classic attacking mould, but with all the modern-day defensive capability to boot.
The 25-year-old boasts the arcing outside breaks and try-scoring potency of a Jeremy Guscott, combined with the kind of gritty tackle-area ability no international 13 can do without.
France coach Philippe Saint-Andre has eased in a clutch of uncapped players with rich potential, none more so than fly-half Jules Plisson who has ousted Frederic Michalak.
France will need the likes of Fofana to guide their new additions into the international arena.
CIAN HEALY (Ireland, prop)
Front-rower Healy hit his bullocking prime in Ireland's last-gasp 24-22 New Zealand defeat in November.
The Leinster prop questioned the validity of the All Blacks performing the Haka away from home in the game's build-up, and used the hubbub that generated as motivation.
Ireland must do away with the psyche of producing big performances against top sides, only to slump in so-called easier contests.
If Healy and Co can reproduce the ferocity and acumen thrust at New Zealand, there could be sparks from Joe Schmidt's men in this championship.
SERGIO PARISSE (Italy, number eight)
Italy's captain and talisman has been among the world's most talented players for the best part of a decade.
The Stade Francais star mixes direct line breaks with unrivalled panache and sleight of hand for a back-row forward.
His accomplished, polished all-round game allows him to be both tub-thumper and playmaker, and he will once again be central to Italy's plans.