I dont know how much I like Mitsurugi here in the long term, as I fully expect it to get hit on the banlist with its recent performances in mind, but for now its the defacto second Ritual engine that doesnt hard lock you to play in a pile like this
While the set-up for the turtle may be appropriately slow, the payoff is explosive, and it could find a home in Modern quite easily
Valgavoth is the main villain for the set and the sets logo, who goes through cycles of harrowing and quiescences
Second, apart from tribal Cats (which may or may not be possible, due to the lack of cards), the only other direction to go is equipment matters, which tends to be an expensive upgrade, since you'll want various Swords, Batterskull, and Stoneforge Mystic and friends