Not as much as you might think. She does have a ton of HP, hits hard, and wont be interrupted much. However, your probably using a poor strategy. After Snow "powers up" a couple of times (and you've raised his chain guage to 3-400%), you should provoke him with Noel to reset Snow's level. So a good SEN, RAV, or Purple Chocobo will do more for you in the fight than V.Lightning.
Or you could go all in and try to stagger Snow as quickly as possible and never see Sovereign Fist.
I do provoke him with Noel, but he seems to "ignore it" somehow and still does his final blow sovereign fist? And I fight him for several minutes and his hp does not deplete one inch, this guy is impossible!
And Purple Chocobo? Never heard of that one, got to check it out. Thanks for the suggestion :)
Snow's Provoke resistance drops each time he charges up. So wait to Provoke until he gets to 300% energy. This will require you to have a strong monster like Goblin Chieftan (one of the best SENs) or Purple Chocobo (one of the best SYNs, also halves damage, and is one of the best monsters period). Having multiple SENs to use provoke helps but isnt totally necessary.
To lower Snow's tension, you need to make him switch targets. If Noel is the current SEN and has already provoked Snow, you need to get Serah or a monster SEN to do a new provoke and force Snow to switch targets.
A much better way is to take out Snow in 1 stagger without any provoking, though this requires strategy and well-infused monsters. I use a team of Purple Choco, RAV Lightning and COM Lightning for this.
A good SYN is mandatory. COM Lightning helps out immensely here as Snow is vulnerable to all the damage multipliers, making Uncapped Damage really shine here. --- Burning with anger, the ArchDevil hits the Archangel for 150% damage.
Thanks for the tips guys! One thing though: I have Sazh as a SYN, can i keep using him or did i just waste money lol?
I heard he's a good early game synergist and he has many offensive buffs. But I don'T like using Synergist monsters. The Sazh-DLC is better used to get a lot of coins. Chronobind is a fast method of receiving coins. You won't unlock the correspodenting Trophy, though.
Sazh is a pretty good SYN, and his Feral Link is excellent for driving up the chain gauge post-stagger. Monster SYNs are valuable because they're the only source of great buffs like Bravery, Faith, and En-spells outside of certain feral links and Auto-buff accessories.