You know, It's kinda surprising no one tried to make their own fantasy version of WT.

>Replace Trion with mana
>Border becomes a magical academy or adventurer guild
>Dungeons appear instead of gates
>Invading races are fantasy themed
>fiends, fae, giants, you name it
>Runes instead of Triggers

Attackers become Warriors
Shooters are Mages
Snipers turn into long-range elemental casters or archers
Trappers could be rune users or summoners

You could even spin it as an isekai:
"MC dies, his little sister is left alone on Earth.
Now he’s grinding his way up to A-Rank in the Adventurer’s Guild, hoping to get on an away mission and start hopping worlds to find his way back to her."

Surprised Isekai authors didn't get to it yet.