Victory Conditions Spider Spawning is far and away the best route to victory in mill-yourself decks, but even if you don't get any Spider Spawnings, or your opponent finds a way to deal with your Spider tokens, the deck can still win with relative ease
Like everything else on a cards type line, supertypes act as markers that can be referenced by other card effects (e.g., Target legendary permanent)
But actually, this isn't ideal for a couple of reasons Firstly, your opponents can crack their fetchlands in response to Hamlet's triggered ability, making it ineffective against any that are already on the field
While Venerated Rotpriest obviously synergizes with the spells you cast, even in the worst case, its a guaranteed Poison Counter
Muldrotha decks generally play a midrange-y game plan trying to fill your deck with a balance of different permanent types to get the most out of its effect