Upgrade Summon

Upgrade Summon is a method of Summon that can summon an Upgrade Monster from your extra deck.

Just like Ritual Spell Cards that can summoned Ritual Monsters, Upgrade Summon can used Upgrade Spells Cards.

To activate this summoning method, you need a monster from the field. Then, you can use an Upgrade Spell to evolve that monster into an Upgrade Monster.

The condition is that Upgrade Monsters must be summoned when they're evolved form their current form and have an Upgrade Spell on it.

Here is a text:

Must be summoned when "CURRENT FORM" was evolved by "UPGRADE SPELL".