Take a look at cards such as Liliana's Specter, Scythe Specter, Unnerve, Syphon Mind, and of course Cackling Fiend
Shiinotic evolves from Morelull
Like Lutri in Commander, Lurruss build-around requirement was not much of a restriction in Vintage
The shield counter text alone won't often be enough to run this in non-Merfolk themed decks, but it'll definitely have a place in any Falco Spara, Pactweaver builds
Red's main source of damage is point-based, making its weakness creatures with high toughness
Here are a few of the best Fusion Summon targets to bring out with this Rock Monster: Blue-Eyes Tyrant Dragon is unaffected by Trap cards and can bring back your Traps from the Graveyard Elemental HERO Brave Neos works well in Elemental HERO decks that focus on Neos cards Invoked Mechaba helps you negate Spell, Trap, and Monster effects