Amber and Amethyst likes to quest early and often. Emerald and Ruby is especially good at delaying your opponents progress early on. Sapphire and Steel is great at quickly increasing the amount of ink in your inkwell. Those descriptions from the quick-start rules for each deck proved true
To go even further, add untap engines to revive multiple creatures per turn and flood the board with resurrected nightmares
Ovika, Enigma Goliath | Illustratioin by Antonio Jos Manzanedo There are 36 commanders in Phyrexia: All Will Be One
You can also use David Xanatos Steel Clan Leader (or other draw-then-discard cards) to put an Item into the discard straight away
In a Two-Headed Giant game, life gained by your teammate won't cause Minwu's last ability to trigger, even though it caused your team's life total to increase
Vrestin, Menoptra Leader This isnt your usual insect commander, since Vrestin, Menoptra Leader swaps black magic out for white