Confusing sentimental value with market value -- Your Base Set Pikachu is not necessarily rare
This can be done by activating Selenia's ability numerous times while the activations are still on the stack, allowing her controller to pay absurd amounts of life, then using the aforementioned spells to topple the life totals of one's opponents

3 Braska's Final Aeon Cecil, Dark Knight Cecil, Redeemed Paladin Chaos, the Endless Choco, Seeker of Paradise Cid, Timeless Artificer Clive, Ifrit's Dominant Cloud of Darkness Cloud, Midgar Mercenary Cloud, Planet's Champion Crystallized Serah Diamond Weapon Dion, Bahamut's Dominant Edgar, King of Figaro Emet-Selch, Unsundered Esper Terra Excalibur II Exdeath, Void Warlock Fang, Fearless l'Cie Firion, Wild Rose Warrior Freya Crescent G'raha Tia Gaius van Baelsar Galian Beast Garland, Knight of Cornelia Garnet, Princess of Alexandria Gilgamesh, Master-at-Arms Giott, King of the Dwarves Gladiolus Amicitia Gogo, Master of Mimicry Golbez, Crystal Collector Hades, Sorcerer of Eld Hope Estheim Hydaelyn, the Mothercrystal Ifrit, Warden of Inferno Ignis Scientia Jecht, Reluctant Guardian Jenova, Ancient Calamity Jill, Shiva's Dominant Joshua, Phoenix's Dominant Judge Magister Gabranth Kain, Traitorous Dragoon Kefka, Court Mage Kefka, Ruler of Ruin Kuja, Genome Sorcerer Lightning, Army of One Lightning, Security Sergeant Locke Cole Lunatic Pandora Matoya, Archon Elder Minwu, White Mage Neo Exdeath, Dimension's End Noctis, Prince of Lucis Omega, Heartless Evolution Phoenix, Warden of Fire Prompto Argentum Queen Brahne Quina, Qu Gourmet

Sivriss plays well with sacrifice and recursion, and adds a little mind game on the side
The two cards are a bit interchangeable now, allowing for more versatility in Humans that can take care of artifacts or enchantments