My standard deck from Guilds of Ravnica. All of the spells except the one copy of Gideon and the three vanguards are from Guilds, so it's also a Boros Legion themed deck.
I loved the mentor mechanic from the moment I saw it, and this deck is just oozing with flavor.
Starting at the one-drop slot we have Goblin Banneret. This seems like a minor/filler creature but it is actually a very important part of our deck. The fact that it has "firebreathing" and mentor means that it will often be the reason we can continue to mentor late game. It also can attack into a stalled board with reckless abandon if we hold up the mana to pump it.
At the two-drop spot we have Sunhome Stalwart, Skyknight Vanguard, and Boros Challenger. The stalwart is a very good creature to put counters on due to the first strike, and the challenger has three toughness which helps us defend if necessary. The option to pump itself, while expensive, will occasionally matter. Both of these creatures have mentor, which becomes very relevant on turn three. The vanguard acts sort of like Legion Warboss in that it creates tokens, but the flying can be super relevant in some matchups. It is also a great target to mentor, and the damage in the air can often give us the final points of reach to close out the game.
At the three-drop slot we have Legion Warboss and Tajic, Legion's Edge. The warboss will drop a token the turn he comes in, which will get a mentor counter from one of our two drops. Then the warboss will either demand removal or win us the game by going wide. Next up is Tajic, who lines up some of our most aggressive games due to his haste and three power. He also protects the rest of the team from burn, which most people I play against seem to forget! Lastly his ability to gain first strike can catch some people off guard.
Our only four-drop creature is Aurelia, Exemplar of Justice. Do I really need to explain this one? She leads the legion to victory quickly if she isn't answered, bringing value as early as the turn she comes down.
By way of removal and combat tricks we have Justice Strike, Response / Resurgence, and Integrity / Intervention. Justice strike is pretty straightforward and very thematic for our deck. Integrity can double as a combat trick, or as a way to continue our mentor train. Intervention can be expensive removal, or burn for the last couple points of damage. Response is more removal, but we don't want to use this mode if it can be avoided. We would rather use resurgence and just beat our opponent down, true legion style.
The one-of's we have are Gideon Blackblade and Chance for Glory. Gideon is a planeswalker that is also a powerful indestructible creature, and chance is like the coolest all or nothing spell ever.
This deck has everything you could ask for, it's pretty budget, completely thematic for the Boros Legion, super fun for casual, and it has more options than most aggro decks which keeps each game interesting. Let me know what you guys think, and if you like the deck let me know with a comment or an upvote!