These are Sagas on their front face, and then transform to the enchantment creature on their backs as their final chapter trigger
This two-mana planeswalker made a big impact in a number of formats, including Legacy, where it was eventually banned
The key is probably in some kind of cost reduction space like convoke since this legendary praetor looks to the mana value
Kiora triggers anytime you cast a spell, not resolve it, so you still get to grab a second spell if your original creature is countered
Creating copies of equipment gives you the tools to overwhelm your opponents, especially since they come into play attached to the creature they were copied from
Merciless Javelineer: Discarding a card isn't free, and needs to be put into a deck with care