Blue has it unconditionally, black lets you trade life for it, green often bases it on your creatures, and red has you discard cards in exchange for a draw, but white has almost nothing
If you dont cast it, put it into your hand. Basically, as long as you use instant speed spells, you can constantly generate value by drawing cards or casting stuff for free, and thats really very hard to beat when youre also messing up everyone elses fun at the same time
Angraths Marauders I think the best play with Angrath's Marauders is to threaten an attack that looks nothing like lethal, slam this down in your first main phase, and end the game there and then
You probably dont want Item Shopkeep in most other decks, but it should be good with the right support
Ancient Imperiosaur is awesome in a deck filled with creatures, since it can hit the board early and with a lot of counters