There are more ways an enemy AI makes it easier for you.

Taunting animation after it scores a hit. This lets the player finish the stun animation and get ready for an attack of her own. It would be very easy to turn off taunting and then stun lock the player.

Repeatedly using attacks that can be countered (or dodged and leaving the enemy open for damage). In crappy cover-based shooters this is the enemy coming out of cover to let you hit them. A competitive ai not select those kinds of attacks. Granted this can be fix with plot.

Telegraphing moves (the windup) so the player has a chance to react. This windup animation is a very important part of difficulty scaling especially in reaction based combat.

It's very easy to make an enemy difficult to play against. But it's very hard to make it a challenging but fun enemy. Part of that is making the enemy do dumb stuff and let the player have a winning move at all.

There are more ways an enemy AI makes it easier for you.

Taunting animation after it scores a hit. This lets the player finish the stun animation and get ready for an attack of her own. It would be very easy to turn off taunting and then stun lock the player.

Repeatedly using attacks that can be countered (or dodged and leaving the enemy open for damage). In crappy cover-based shooters this is the enemy coming out of cover to let you hit them. A competitive ai will not select those kinds of attacks. Granted this can be fixed with plot.

Telegraphing moves (the windup) so the player has a chance to react. This windup animation is a very important part of difficulty scaling especially in reaction based combat.

It's very easy to make an enemy difficult to play against. But it's very hard to make it a challenging yet fun enemy. Part of that is making the enemy do dumb stuff and let the player have a winning move at all.