Rona, Herald of Invasion // Rona, Tolarian Obliterator

To transform a permanent, turn it over so that its other face is up. Only transforming tokens and permanents represented by transforming double-faced cards can transform. (See rule 712, “Double-Faced Cards.”)

Although transforming a permanent uses the same physical action as turning a permanent face up or face down, they are different game actions. Abilities that trigger when a permanent is turned face down won’t trigger when that permanent transforms, and so on.

If a spell or ability instructs a player to transform a permanent that isn’t represented by a transforming token or a transforming double-faced card, nothing happens.

If a spell or ability instructs a player to transform a permanent, and the face that permanent would transform into is represented by an instant or sorcery card face, or is a transforming token that was created with an instant or sorcery face, nothing happens.

Some triggered abilities trigger when an object “transforms into” an object with a specified characteristic. Such an ability triggers if the object either transforms or converts (see rule 701.50) and has the specified characteristic immediately after it does so.

If an activated or triggered ability of a permanent that isn’t a delayed triggered ability of that permanent tries to transform it, the permanent does so only if it hasn’t transformed or converted since the ability was put onto the stack. If a delayed triggered ability of a permanent tries to transform that permanent, the permanent does so only if it hasn’t transformed or converted since that delayed triggered ability was created. In both cases, if the permanent has already transformed or converted, an instruction to do either is ignored.

Some spells and abilities refer to a “transformed permanent.” This phrase refers to a permanent on the battlefield with its back face up that’s also a transforming double-faced card or a transforming token. A permanent with its front face up is never considered a transformed permanent, even if it had its back face up previously.

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.