If the average nonland CMC of your deck is around 2.0, play 23 lands
Hes limited to the first instant and sorcery you cast per turn and you need a body to sacrifice to make it happen
In fact, if youre into big risk, big reward strategies, this is often one of the more exciting ways to go
Worst case scenario, run it out as a slow 3-color land
Liliana, Heretical Healer is an acceptable if unexciting creature, so assuming she does reasonably well on the rest of the tests, Liliana, Heretical Healer could still end the course with a decent grade
Many players would reach for burn, but that mechanic has a close cousin in life loss cards that dont care about anything so petty as damage or creatures