sure, it could have just put more counters on Jace or improved the outcome on your 0 ability some other way, but creating a second Jace opens up so many more possibilities for both players
add to your hand or Special Summon, 1 "Uria, Lord of Searing Flames", "Hamon, Lord of Striking Thunder", or "Raviel, Lord of Phantasms" from your GY, ignoring its Summoning conditions
Malevolent Hermit saw quite a bit of play throughout its three years in Standard as a way for tempo and midrange decks to fight against control, with its front half sacrificing itself to counter non-creature spells and its back half making your non-creature spells uncounterable
theres no need to spend a lot of cash on premium dual lands
You can only use this effect of Critias the Legendary White Dragon Knight once per turn
Well get more into the boss Monsters in the Extra Deck, and which cards bring the power, later on