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.