For example, Karador, Ghost Chieftain wants to tap out on your turn, and the two cards are simply antithetical
Good stuff for carving out a new place in this color combo - tappers matter
Do they synergize with the other thallids spore counters

Ayara, First of Locthwain Ayara, Widow of the Realm Blightsoil Druid Briarblade Adept Compleated Huntmaster Creakwood Safewright Dawnhand Dissident Dawnhand Eulogist Deadbridge Shaman Deathknell Berserker Drider Duskwielder Elderfang Disciple Elderfang Ritualist Elvish Doomsayer Elvish Dreadlord Exquisite Huntmaster Eyeblight Assassin Eyeblight Cullers Eyeblight's Ending Gilt-Leaf Winnower Gloom Ripper Gnarlroot Trapper Haunt of the Dead Marshes Hired Hexblade Hunter of Eyeblights Infestation Sage Iron-Shield Elf Koma's Faithful Lys Alana Scarblade Maralen of the Mornsong Melancholic Poet Miara, Thorn of the Glade Moonglove Extractor Moonglove Winnower Nadier's Nightblade Nadier, Agent of the Duskenel Nightshade Harvester Plague Witch Prowess of the Fair Ruthless Winnower Scarblade Elite Scarblade Scout Scarred Vinebreeder Shadowheart, Dark Justiciar Skemfar Avenger Skemfar Shadowsage Thornbow Archer Thornmantle Striker Twilight Diviner Unscrupulous Agent Viconia, Drow Apostate

Just keep in mind that this Deck is most likely in a winning position to consider Level 11 Synchro plays so PEP may not have its protection
This category I'm delineating as cards that either flip using the old werewolf tech, using mana, or mostly instantly (Skin Invasion, Garruk Relentless etc)