Part combat trick, part Edgar-Markov-for-Humans-attack-trigger, Karvanista is an extremely solid card
What he means by this, it seems, is that not all numbers are valued equally
It can be effectively employed in a range of control and combo decks, especially where you can easily generate creatures to sacrifice
If a triggered ability is linked to a second ability, additional instances of that triggered ability are also linked to that second ability
Clearly, Wizards of the Coast put a serious effort into this set and counted on it being a big hit, and so far, it seems to be working
That doesn't generally bother many players