Black Waltz No
If a card tells you to do something to a certain number of the top cards of your deck, and you have fewer cards than that left in your deck, do whatever you are supposed to do to the cards that you have left and continue play as normal
While its not quite as popular as Vivi Ornitier, Kefka has a rich competitive history, consistently topping events
And if toughness is your goal, you need some of the highest-toughness cards out there like Unhallowed Phalanx, Charix, the Raging Isle, and Kharis & the Beholder (that last one not being legal for tournament play)
Toughness is how much damage a creature can take before it goes down for the count
In the same way youd focus on a lifelink player when theres no clear threat, you should expend resources on the Goad player while attacks are open