With the Necroduality trigger still on the stack, sacrifice Rot Hulk to Carrion Feeder, then let the original Necroduality trigger resolve, creating a token copy of Rot Hulk
Varis used all of his monsters to Link Summon "Topologic Bomber Dragon", a Cyberse monster that he found amusing to use against Playmaker's Cyberse monsters
If theres a way to cheat them out earlier in a game then theres a pretty good chance theyll see some play
If this card is in your GY: You can Tribute 4 monsters, the 2 in the Extra Monster Zones and the 2 in the center Main Monster Zones, and if you do, Special Summon this card
In the case of Muldrotha, if our important cards are 5cmc, we want our ramp cards to be castable on turns 1-3 so we can play our engines a turn early