You cannot Special Summon monsters from the Extra Deck.
When you Tribute Summon a monster: You can activate 1 of these effects;
● Add, from your Deck to your hand, 1 monster with 2400 ATK and 1000 DEF with a different name from that Tribute Summoned monster.
● Add, from your Deck to your hand, 1 monster with 2800 ATK and 1000 DEF with a different name from that Tribute Summoned monster.
The Tribute Summoned monster must be face-up on the field to activate and to resolve this effect.
You can only use this effect of "Return of the Monarchs" once per turn.