The plot armor in this novel also could be described simply with "A Guardian when he's not strong enough and no life threatening battle with those too much stronger with him (other than when he is in his own dimension)
Nearly always meet the same level enemy (sometimes one stage higher) except when the guardian's presence is there.
We would see a nice character development when we see it from each character's perspective but the interaction between characters would not differ much even after the development happen that make us think as if they're still the same as when they're in the early chapters (including his harem).

NO RACISM.. (Except for baddy aliens) such a nice thing after a while thankfully
Nice gags
The world building is actually not bad and we also have a quite complete system (a bit too all encompassing system when we think that every civilized creature from different species have the same system, not dividing it as a mere universal power standard but it's still fine)
A nice with sometimes valiant, brave, tacky, or even funny approach by the main character when doing things and described with detailed explanation makes us want to see more.
The OP ability gives him unreasonably fast leveling but quite reasonable after we thought of his ability a bit fun when we see the scope of ability, see the combinations, and think what might come next.