I want to run a one-on-one "epic fantasy superhero" game with a single PC and no companions...

>One-on-one RPGs are no more invalid than traditional "one GM and a group of players" systems.
I lost.

Don't be a prick, dude. They are a fine way to play a game.

They're not.

>example from Anima
Well every type of character has some kind of resource they use to power their abilities. So a high level mage is going to have a lot of Zeon (mana) with which to cast many spells, but the amount is ultimately finite. It's probably better to cast cheap, high damage spells in most situations, but better to drop a big, high cost area of effect spell on top of an army. In either case the resource has to be managed at the level of the reserve pool and in terms of ability upkeep.

In addition to abilities, characters also have better attack and defense values than mooks, so they can block a string of attacks without any problem, byt at a certain point numbers become dangerous because you take stacking penalties, so then they have to think about taking a hit in order to preserve their ability to block a more dangerous attack or something.

In general Anima offers a great deal of choice in combat and character design.

Are too.

Nuh-uh!

>So a high level mage is going to have a lot of Zeon (mana) with which to cast many spells, but the amount is ultimately finite.

I am fairly leery of "single point pool" resource management system. D&D 3.5's psionics, while certainly better-designed than its Vancian casting, still promoted a paradigm of spamming a couple of a character's best combat powers.

D&D 4e's power point-using psionicists likewise fell into a pattern of spamming one or two of their best powers.

Even Legends of the Wulin still suffers from this with some of its builds, most notably Boundless Prosperity Manual builds and Heaven's Lightning builds.

What does Anima do to actively promote mixing things up with such point pools?

Yeah huh

I would suggest the Hero system, its phases system and Endurance management makes for tactical combat, it's mechanically similar to GURPS but scaled for power levels, it's subtractive DEF values and the way defenses are weighted vs attacks point wise means the character should be able to be set up to be fairly safe from dying.
Downsides are character creation is involved, but if you only have to do one character then that should be less of a problem. You will also have to do some basic multiplication and (gasp) division, but mostly in character creation, but since you're only running one character, you might be able to just handwave the points and give them what you think is appropriate.

The resource pools are not the place to stop spamming the "best" power, to prevent that you have to make all the powers useful in different situations.