Attacking creatures with equal (or higher) power to the blocking creatures defense will cause the blocking creature to die
At this point, things are getting interesting for sure
Theres also Giant Opportunity, a green sorcery that creates a 7/7 green giant if you sacrifice two Foods, essentially simulating what happens if you eat two magic beans
The other reason to not overload on learn cards is there are diminishing returns casting Lessons
Enchantment Necrosynthesis Enchant creature Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature." When enchanted creature dies, look at the top X cards of your library, where X is its power
For example, the Giants Unleashed mission wants you to get Regigigas, Regirock, Regice and Registeel while the Battle with Champion Cynthia mission requires Cynthia, Garchomp and two Spiritomb