I'm not sure how good Mankrik is in this deck. Also feel like you are forcing too hard to meet the Ritual of Doom condition with cards like Fiendish Circle and Necromancer. With the natural zoolock gameplay you can already do the ritual consistently. Just my 2 cents :) I also made my own version of zoolock for Barrens, feel free to hop in and critique :)
https://outof.cards/hearthstone/decks/22979-year-of-the-gryphon-zoo
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