Magic Resistance: This creature has advantage on saving throws against spells and other magical effects.

Legendary Resistance (4/Day). If the Ysguardian fails a saving throw, it can choose to succeed instead.

Towering Presence: When this creature is fighting a creature two size categories or smaller than it, this creature has advantage on all attacks against those creatures.

Siege Monster: This creature deals double damage to objects and structures.

Incredible power: All attacks deal an additional 10 melee attack damage.

Intimidating Presence: Creatures within a 60ft of this creature must make a wisdom saving throw DC 16 or be frightened.

Multi-attack. This creature can make three attacks, one Gore, one Great Club, and one bite. The creature can replace any of these attacks with an earth binding javelin attack.

Gore Attack: To hit +18, within 10ft, 6d10+20 piercing damage

Great Club Attack: To hit +18, within 10ft, 2d10+20 Bludgeoning damage

Bite Attack: To hit +18, within 5ft, 2d8+20 piercing damage

Earth Binding Javelin: To hit +18, within (60/240) 4d10+10 force damage and if the creature is flying, it is knocked out of the sky. A creature knocked out of the sky takes falling damage equal to 1d6 per 10 ft it falls.

Fighting Dirty. The creature runs its Great Club across the ground to knock a creature prone within a 10ft range. The two creatures make a strength check, if this creature wins it knocks the target prone, but if the target wins this creature losses its balance and falls prone.

Running Charge: The creature charges an additional 40ft. If this provokes an attack the creature takes the attack but is immune to the damage taken in this way.

This creature has multiple reactions equal to half the number of people it is fighting rounded down:

Shake it off and give it back: When the creature gets targeted for a melee attack the creature can use its reaction to roll 1d20+10 to mitigate the oncoming damage. If the damage is reduced to 0 the creature can immediately make one Great Club attack against the target hitting it.

Spell Slayer: When a creature casts a spell within 40ft of it, the creature can move up to the target and make one Great Club Attack, forcing the creature to make a con save DC equal to 10 plus spell level. If failure the spell is wasted. On success the spell goes off.

The creature can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. The creature regains spent legendary actions at the start of its turn.

Great Club attack (1 action): The creature can make one Great Club attack against a creature within range.

Charge (2 actions): The creature runs toward its enemies up to half its speed, any creatures it charges through must make a strength saving throw DC 21. On a failure, the creature takes 7d10 piercing damage and is pushed 20ft away and knocked prone. On a success, the creature takes half and is not prone or pushed.

UNSTOPABLE FURY (3 actions): In a raging fury the creature swings it great club around in a 10ft area around itself. Each creature is targeted with a great club attack taking the damage plus an additional 2d10 bludgeoning damage.