The Planeswalker Lolth, Spider Queen gains a loyalty counter every time one of your creatures dies, with loyalty abilities that spend one life to draw a card (+0), spawn buffed-up Spider creature tokens (-3), and create an Emblem (appropriately at a loyalty cost of -8) that, if you did an opponent anywhere between one and seven combat damage in a turn, bumps that damage up to eight
With a big enough army, you can push through all your opponents' defenses to poison out all your opponents in a single turn
You can play whatever color you like or choose the creature type to get the benefit
If you don't, the ability won't trigger at all
The thing is that Glint-Eye can turn the spells you will want to play into cards via his discard ability
You just need a way to get more out of them, and you can do whatever you want with the ten best flicker cards in MTG though