While Greymoor added a fresh new take to this aspect of the game, it still falls behind in a lot of areas such as a couple of 'poor' skills and a very unbalanced negative to positive ratio of stage effects (hence why you will see a lot of people recommending builds or vamp use at no higher than stage 1).
Here are some possible changes that could be added too make this a interesting and fun playstyle;
Stage adjustment:
The Current Stage perks and handicaps don't balance out with skill cost, vulnerability to fire and health regen all being hit hard for the sake of vampire abilities being cheaper. As there is not an abundance of vampire skills, there is not a lot of ability flexibility in terms of justifying players to advance to stage 4 to get a full benefit.
To fix this we can provide a better stage equilibrium, This can be done by;
-Adding a Incremental damage/ critical rate buff per stage, balanced in a way much like Thrassians work, players become very dangerous in both PvE and PvP, but are subject to certain weaknesses. The increase should be large enough to justify the increased normal ability cost, which appears to be the main obstacle for builds relating to Vampire. Obviously the figures can't be too high either otherwise we encounter a new problem.
-A new Negative is added to create more player build diversity in PvP to counteract Vampires. Depending on stage, Players will receive additional damage from Fighters Guild Skills, but only if the user is 'Human'. This should create a really interesting interaction between players in PvP situations where high stage Vampires may be used for larger amounts of damage, but can be hit very hard by Fire AND Fighters Guild skills. plus it suits a theme.
-Vampire Ultimate benefits from an duration increase per stage, Higher stages allow for players to remain in Scion form longer.
Abilities:
There are a few really nice abilities in the vampire line, others are mediocre or simply not useful, a few tweaks can be added to improve this and make skills more impressive and useful.
Here are a few examples;
-Perfect Scion Also receives a Timer much alike the Werewolf mechanic, however it is much shorter and is kill based rather than dependent on 'feeding'. The timer is short to support a very aggressive playstyle that rewards players for slaughtering enemies like a true monster. this effect along with the stage 5 benefit should give player a nice trade between damage and sustain options for morphing this ultimate.
- Vampiric Drain is perhaps one of the most lackluster skills in the lineup, and needs serious rework to bring it more in line with other skills. To improve the skill, the damage is increased and brought in line with that of Radiant Oppression of the Templar skill line, serving as a Vampiric execute equivalent with a heal. Morphs carry the same effect.
- Eviscerate is a VERY nice skill, and does not need any changes, however it could use more diversification for more uses., The Ability and it's morphs are granted a ranged alternate use. The ability icon changes (much like a few other skills like 'grim focus') depending if the player is in melee range and the ability becomes ranged depending on this distance. this should diversify play styles with the skill as a DPS Spamming skill. Traits can change depending on range making the skill more interesting.
-Elusive Mist has invisibility added for a couple of seconds after activating skill, this may justify the skill more for 'squishy' Characters to duck out of combat for a safer escape.
Other:
There are always more ways to create a more interesting experience for this aspect of the game, adding more Vampire specific item sets (as well as new Mythic items and monster sets) that largely benefit Vampires only should REALLY expand builds. Buff Foods and potions could also be added to make the aspect more creative.
This Concludes the Suggestion, while not likely it will ever be considered, it should serve as a discussion for players who wish to expand on their thoughts and changes they wish to see in relation to the Vampire role in ESO
Take Care!
Jamaroo