Onimusha: Way of the Sword combat basics: block first, then strike

Against your first enemy, avoid mashing attack. Focus on one target, watch the wind-up, hold guard for a block, then make one one-handed counter when the enemy stops and create space. Once comfortable, practice parry timing and heavier attacks.

Find your own inputs first

Try the inputs in a safe spot and follow the on-screen tutorial. Capcom confirms keyboard-and-mouse support on PC; the current control menu is authoritative for your own setup.

A one-minute practice routine

1. Find one ordinary enemy you can face alone, lock on and keep enough distance to see the wind-up.
2. Hold guard for one block. Repeated blocking consumes stamina, so watch the gauge instead of holding guard indefinitely.
3. When the attack ends, make one one-handed strike, then return to guard or make space. One-handed strikes are easier to land; two-handed attacks hit harder but are easier to evade, so save them for a clear opening.
4. Once ordinary blocks feel consistent, press guard just before impact to practice a parry. Counter during the brief opening; if the timing fails, return to ordinary blocks rather than rushing into Issen practice.

Unarmed attacks and grabs do not all have the same defensive answer: watch the tutorial and practice the corresponding dodge. If several enemies surround you, move to create space instead of taking damage to finish a combo.

Sources: in-game combat and control tips, Capcom release FAQ and controller support.

One community control listing gives PC default guard as right mouse, and controller guard as Square/X in the face-button layout or L1/LB in the shoulder-button layout. Layout or remapping can change this: check your own settings. Control reference.