Eight mana for a 5/5 flying, lifelink, haste, exalted creature is fine, but being able to convoke this onto the board faster thanks to your army of vampires makes this a fun bomb to drop
Topography Tracker A creature that creates tokens and provides ramp
Im not sure, but it might have had some relevance in the format back in the day
Effects that modify or replace the cost to cast a spell (such as flashback or casting a spell without paying its mana cost due to suspend) don't affect the spell's mana value, so they won't change whether Lavinia's first ability restricts that spell from being cast
Radiant Destiny becomes an Always Watching, which was a great pairing with the exert mechanic (or any creature card really)
During your first turn, add a card to your Inkwell and play a 1-cost card if youre able to