Things are getting serious
The first few issues of the X-Men are often enjoyable reads but the events depicted were relatively inconsequential. The X-Men encounter an evil mutant, the X-Men fight said evil mutant, they get to go home. They encountered a public bemused with their costumes but ready to shake their hands, flirt with them or thank them for a job well done. This is the issue which establishes that wider humanity treats their mutant offshoots with a mix of hatred and fear. Treating us to a disturbing scene of a young Scarlet Witch about to be lynched by an unnamed mass of European peasants.
This is the issue that actually gives "evil" mutants some depth, and introduces some shades of grey. While introducing the Brotherhood of Evil Mutants and the tensions between them.
* Magneto is a familiar face. But steps up from being a somewhat generic villain to a major leader and potential world-conqueror. With apparently some psionic powers of his own. He encounters Xavier on a mental plane and the two constrast their different dreams before declaring war. He later senses Xavier's approach mentally. This issue also introduces his dictatorial behavior as a leader and his potential for genocide, ready to annihiliate Santo Marco and its inhabitants before letting them escape his grasp.
*Mastermind seems to be the MVP of the Brotherhood in this issue. His illusion of an invading army subdues the people of Santo Marco much faster than Magneto's stolen weaponry could. He takes the Beast out of battle and later terrorizes all the X-Men with his realistic illusions. Pointing out "There are times when a clever illusion can be more effective than mere brute strength". His leacherous behavior towards Scarlet Witch is established, though it is refreshing to see she can hold her own in this relationship.
*Quicksilver and Scarlet Witch are established as reluctant villains. Scarlet Witch owes her life to Magneto and has joined him out of obligation. Quicksilver is simply following her. They are firmly established as very protective of each other. Pietro is prepared to face any of his teammates rather than let her get insulted, much less hurt. When Angel knocks out Pietro, Wanda seems to go berserk and takes down the flying X-Man in seconds.Note that it is Quicksilver who saves the day by the end of the issue, defusing Magneto's nuclear bomb before leaving.
*Toad seems to be the weakest member of the team here, and his characterization is that of a regular "toadie". He sucks up to Magneto, reports on his teammates misbehavior, that sort of thing. Otherwise he doesn't play much of a role. Other that a surprise attack on the Beast, he doesn't even participate on the action.
The X-Men continue with their typical characterization, with the only new elements being Angel feeling strongly attracted to Wanda and Professor X coming off more as a parental figure to his students. Not to mention risking life and limb for them. There are still plenty of good moments for them here.
