Unfortunately, I dont see quite enough raw power in Assassins Creed to surge the assassin archetype into Constructed relevance, although one or two of the cheaper creatures might find their way into Modern
Say you kill my Vorinclex, Monstrous Raider and your Summon: Primal Odin has two lore counters
The insect Mazirek, Kraul Death Priest is a Golgari commander who ties all of this together, putting a +1/+1 counter on each creature you control whenever an opponent sacrifices a permanent
I enjoy when commanders offer you multiple different avenues so youre not always locked into your deck trying to play out the same way each time
Unlike you, Ursula can ink as many cards per turn as she needs to
Lastly, Nissa, Worldsoul Speaker is a great way to produce energy