A villainous statblock

I have made a ... well, a villain, of sorts. He's the leader of a criminal organisation, but he's also employer who secures income (also legal income) for quite a lot of people. And he's the kind of criminal who takes care of his own.

Also, if you're a player in my campaign, this is not for you! Eyes off! :p

So Mr. Seasalt, the notorious leader of the Blessed Guild of Porters, Dockworkers and Longshoremen, is essentially a rogue. 

I play essentially no official games. I have no idea what could be like ... lair actions, or legendary actions. I'm not even sure those are the right terms.

Can you give me examples of what a boss like this could be capable of? As an aside, he already has the best of what the Rogue class would give him, Evasion, Sneak Attack, Stealth, and so on.

You can look at the extant creatures with legendary and lair actions for examples.

For legendary actions for a rogue crime boss type, I could see things like getting to move his base speed without provoking OAs. Probably making an attack.

Then something special for some real zip. Maybe calling in some allies — a couple really low CR thugs — to help. But that last one would probably use all of his legendary actions for that round. 

Or something to manipulate the terrain, like a little 5’ square fog cloud as he disappears in a puff of smoke. Or he knocks over a bunch of shipping crates to change the shape of the battlefield by basically creating a new wall while also making a new passage.

Your Crime Boss could have Trait such as Legendary Resistance, Legendary Actions, Multiattacks, Spellcasting as well as Regional Effects within the Porters, Dockworkers and Longshoremen Guildhall. I'd look at different monsters statblocks for ideas.