This is a Dina life-gain/drain deck with a bit of an unconventional twist.
While most decks with Dina at commander make liberal use of her sacrifice ability as part of an aristocrats theme, this deck tries to stack as many lifegain triggers as possible through enchantments and creatures/artifacts that tap to gain life. The primary advantage to this approach is that it creates a snowball effect in which each successive turn drains greater and greater amount of life with no additional investment of mana. Likewise, in a 4-player pod, Dina has the advantage over other life-gain/drain commanders like Vito, Thorn of the Dusk Rose because her lifedrain triggers hit everyone at the table equally. This gives you a 3-1 ratio for every lifegain trigger and keeps you from making enemies since you are not targeting any single person at the table.
Some key drawbacks to this deck include a weakness to Voltron decks and a susceptibility to commander damage. While this deck is geared towards lifegain triggers and not necessarily gaining tons of life, that small buffer of additional life is important since you have weaker defense against creature-based damage. Thus, Voltron decks and decks with the ability to win via commander damage are a serious threat that need to be dealt with through removal spells and table politics. Lastly, spells and creatures that prevent you from gaining life, like Havoc Festival will completely lock you out of the game and must be dealt with as soon as possible.
Synergy Pieces
Belbe, Corrupted Observer: Belbe is one of the best ramp pieces in this deck and can make a serious impact when played early. Since every lifegain trigger will hit all of your opponents, Belbe will almost always be generating an extra six generic mana every turn. Yes, your opponents will also receive some benefit from her, but they will rarely get as much value as you and what mana they do receive will keep them from targeting her with removal.
Blood Artist & Marauding Blight-Priest & Epicure of Blood: These guys are essentially extra Dinas that allow you to double-up on your life-gain/drain triggers.
Kamahl's Will & Inscription of Abundance & Devouring Tendrills & anything-else-that-fights-or-deals-direct-damage: These removal spells will do double duty when you have creatures with lifelink. Get one lifegain trigger while removing a creature, and then swing in for another trigger from the same creature.
All Stars
Wolverine Riders: This card creates an elf token on EVERY upkeep, not just your own. That means that you are getting four lifegain triggers each round and some 1/1 chumps that can block attacks. If you also happen to have a Wellwisher on the field, then you can gain some serious life as an added bonus.
Thieving Amalgam: Like the previous entry, this is another card that gets you value on each opponents upkeep. Granted, this is one of the few cards that does require you to pay mana for Dina's sacrifice ability, but the upside is that each card you steal is manifested and can potentially be turned face-up for big value. Be warned, people hate having their cards stolen and this card will attract removal spells with regularity.
Revenge of Ravens: There are a lot of enchantments in this list that allow you to gain life passively, but this is the only one that also discourages players from attacking you. This creates a separate trigger for EACH creature that attacks you, so it completely negates token decks and decks that win by swinging wide.
Wincons
Zuran Orb: Since it costs no mana cast and does not need to be tapped in order to use, this card can easily close-out games when your opponents are at less than half of their starting life totals. Be warned, however, that opponents can respond to your land sacrifice at instant speed, so sacrifice each land individually and never all at once. Nothing feels worse than sacrificing almost all of your lands just to have Dina get removed.
Death Frenzy: Although not always enough to win the game, this card will almost always provide good value and can frequently close-out games if there are a lot of creatures on the board. Since each creature who dies to this spell counts as a separate trigger, you will drain a lot of life and you get the added bonus of being able to swing with any of your own creatures that survive. Either your opponents block, which causes creatures to die and you to gain more life, or they don't and you get to score some cheap damage.