Nyxborn Hydra

Reach is a static ability.

A creature with flying can’t be blocked except by creatures with flying and/or reach. (See rule 509, “Declare Blockers Step,” and rule 702.9, “Flying.”)

Multiple instances of reach on the same creature are redundant.

Trample is a static ability that modifies the rules for assigning an attacking creature’s combat damage. The ability has no effect when a creature with trample is blocking or is dealing noncombat damage. (See rule 510, “Combat Damage Step.”)

The controller of an attacking creature with trample first assigns damage to the creature(s) blocking it. Once all those blocking creatures are assigned lethal damage, any excess damage is assigned as its controller chooses among those blocking creatures and the player, planeswalker, or battle the creature is attacking. When checking for assigned lethal damage, take into account damage already marked on the creature and damage from other creatures that’s being assigned during the same combat damage step, but not any abilities or effects that might change the amount of damage that’s actually dealt. The attacking creature’s controller need not assign lethal damage to all those blocking creatures but in that case can’t assign any damage to the player or planeswalker it’s attacking.

Trample over planeswalkers is a variant of trample that modifies the rules for assigning combat damage to planeswalkers. The controller of a creature with trample over planeswalkers assigns that creature’s combat damage as described in rule 702.19b, with one exception. If that creature is attacking a planeswalker, after lethal damage is assigned to all blocking creatures and damage at least equal to the loyalty of the planeswalker the creature is attacking is assigned to that planeswalker, further excess damage may be assigned as the attacking creature’s controller chooses among those blocking creatures, that planeswalker, and that planeswalker’s controller. When checking for assigned damage equal to a planeswalker’s loyalty, take into account damage from other creatures that’s being assigned during the same combat damage step, but not any abilities or effects that might change the amount of damage that’s actually dealt.

If an attacking creature with trample or trample over planeswalkers is blocked, but there are no creatures blocking it when damage is assigned, its damage is assigned to the defending player and/or planeswalker as though all blocking creatures have been assigned lethal damage.

If a creature with trample over planeswalkers is attacking a planeswalker and that planeswalker is removed from combat, the creature’s damage may be assigned to the defending player once all blocking creatures have been dealt lethal damage or, if there are no blocking creatures when damage is assigned, all its damage is assigned to the defending player. This is an exception to rule 506.4c, and it does not cause the creature to be attacking that player.

If a creature without trample over planeswalkers is attacking a planeswalker, none of its combat damage can be assigned to the defending player, even if that planeswalker has been removed from combat or the damage the attacking creature could assign is greater than the planeswalker’s loyalty.

Multiple instances of trample on the same creature are redundant. Multiple instances of trample over planeswalkers on the same creature are redundant.

Bestow represents a static ability that functions in any zone from which you could play the card it’s on. “Bestow [cost]” means “As you cast this spell, you may choose to cast it bestowed. If you do, you pay [cost] rather than its mana cost.” Casting a spell using its bestow ability follows the rules for paying alternative costs (see 601.2b and 601.2f–h).

As a spell cast bestowed is put onto the stack, it becomes an Aura enchantment and gains enchant creature. It is a bestowed Aura spell, and the permanent it becomes as it resolves will be a bestowed Aura. These effects last until the spell or the permanent it becomes ceases to be bestowed (see rules 702.103e–g). Because the spell is an Aura spell, its controller must choose a legal target for that spell as defined by its enchant creature ability and rule 601.2c. See also rule 303.4.

If a bestowed Aura spell is copied, the copy is also a bestowed Aura spell. Any rule that refers to a spell cast bestowed applies to the copy as well.

When casting a spell bestowed, only its characteristics as modified by the bestow ability are evaluated to determine if it can be cast.

As a bestowed Aura spell begins resolving, if its target is illegal, it ceases to be bestowed and the effect making it an Aura spell ends. It continues resolving as a creature spell. See rule 608.3b.

If a bestowed Aura becomes unattached, it ceases to be bestowed. If a bestowed Aura is attached to an illegal object or player, it becomes unattached and ceases to be bestowed. This is an exception to rule 704.5m.

If a bestowed Aura phases in unattached, it ceases to be bestowed. See rule 702.26, “Phasing.”