The main gameplay loop is about establishing early board presence with supportive glimmers, then leveraging Sapphires resource tools to unleash mid- to high-cost characters that snowball Lore quickly
Sidisi, Undead Vizier Sidisi, Undead Vizier might be the best commander to try the Bolas's Citadel and Aetherflux Reservoir combo, though it's also just a generically strong creature with decents stats
Liliana, Deaths Majesty Liliana, Death's Majesty is a solid roleplayer that allows you to constantly create tokens and keep a reanimation effect when able
I've barely mentioned half of them, with further objective types, event objectives available for limited time - but again, very generous and doable challenge - letting you pick up some special cosmetics like playmats and card covers
On a side note, I think this is what Nadu, Winged Wisdom was originally going to be
Does Najeela, the Blade-Blossom use any infinite combos