I like the white deck, i'd drop the
Mirran Crusader though to make this standard legal. He's a good card but he's also the only thing holding you back from being able to play it competitively.
it also looks rather inconsistent you'll want to try to have multiples of a given creature or spell to increase the likelihood of seeing it. Having a plan to win is important and if you can't get the pieces to support that plan the deck has a much harder time winning. Right now it looks like you're trying to use
Seraph of the Dawn to whittle away your opponents life while bolstering your own. Given that strategy I'd opt for another and drop your
Archangel. While it is a strong card 7 mana to get it out is rather on the pricy side for many formats and makes it more likely to clog up your hand if you get it before you have 7 mana.
The Goblin deck looks quite functional, but given the inclusion of a full set of
Krenko's Command there are a few creatures that look a little out of place. Given that you named the deck after
Krenko, Mob Boss I'm assuming he's your win condition. With the plan being to have Krenko pump out as many Goblins as possible and swinging with a ridiculous number of attackers
Fire Elemental,
Bladetusk Boar, and
Forge Devil aren't working for you as well as some more cheap goblins would. Krenko requires goblins beside himself to work well, so being able to keep pouring them out until he gets there is a necessity. while none of the 3 i listed are bad in the deck I'd be looking to remove them to speed up the deck. Ideally a Krenko deck shouldn't need more than 4 mana to work. It's not something that needs to be fixed immediately but I'd keep an eye out for some goblins i could slot into this deck.
I would however recommend hitting up your local card shop for another Krenko or two just to improve your chances of seeing him. As this deck's Win Con you want a good chance of seeing him but not so many that he'll clog up your hand. He is legendary after all so you can only have one of him on the field.
Both deck have room for improvement, but look like they should work pretty well. Hope this gives you some idea of how to improve them.