Rakish Heir does not work properly. It's effect triggers properly each time a vampire deals combat damage to a player, and each vampire that dealt damage is referenced correctly, but no +1/+1 counters are placed after it resolves.
EDIT:
Necropolis Regent,
Shaman of the Great Hunt, and
Stensia Masquerade are also not working correctly. Again, the ability triggers properly, but no counters are placed. I doubt that this problem is isolated to these four cards.
EDIT 2: This bug does not occur in v1.6.10.
FINAL(?) EDIT: The source of the problem is the "TriggeredSourceLKICopy" definition. As of v1.6.11, each affected card defines TriggeredSourceLKICopy as the receiver of the +1/+1 counter, whereas each card in v1.6.10 instead defined TriggeredSource. Replacing TriggeredSourceLKICopy on an affected card with TriggeredSource resolves the problem for that card.