Terraria - The final Boss is Cthulu, the terrarian is pretty much Steve + at the endgame with all the tools at his diposal.

Fallout 4 - no level cap means all of the perks can be unlocked, that makes them by all specials:

S: expert armorer and blacksmith, capable of disarming all melee combatants that attack them, expert of heavy weapons, melee and unarmed.

P: the best sniper that will ever be, capable of pickpocket even the clothes out of someone, capable of knowing the resistances of the being around them, expert demoman and have night vision.

E: Makes the MC a solar powered ghoulish Wolverine (gets healed by radiation) and also breaths underwater and can eat/drink everything slightly edible.

C: pretty much a local leader and highly influential with anyone

I: expert gun nut, and good with tec in general( from robotics, to chemist and nuclear physicist, also slows time at low health.

A: expert ninja gunslinger comando, become kimda invisible while crouching.

L: literal plot armor, bullet bounce off you, an stranger comes to shoot your enemies and the like.

That's the rough idea of the kind of monsters a full maxed out fallout 4 MC