In either of your own main phases, you can special summon lava golem. Rather than offering the cost from your own side of the field, Lava Golem says to use the opponent's monsters. So you send the opponent's two monsters to the graveyard and place Lava Golem on their side of the field. Either player can try to negate it, in which case it will be destroyed and go to your graveyard.
Chat with our AI personalities
Lava Golem's own special summon effect can only special summon itself to the opponent's side of the field. Like other 'can only be special summoned by..' monsters, if you summon it correctly, and it is then destroyed, it can be brought back to the field by cards like Monster Reborn. In Lava Golem's case, it will be special summoned to your side of the field if you do this.
Unless stated otherwise (Plaguespreader Zombie for example) a monster's special summon is done from hand only. Lava Golem must be in your hand, for you to be able to special summon it using the listed text on the card.
Yes. An opponent's Obelisk or Ra can be tributed as cost for your Lava Golem. It is not an effect, nor does it target, which is why Obelisk is not protected from it. Ra has no protections anyway apart from during his summon.
Ancient gear golem is easiest summoned using geartown which allows you to summon ancient gear monsters with one less tribute, ergo, you only need one monster to tribute to summon ancient gear golem. Ancient gear golem cannot be special summoned which make things difficult. Cards such as spell gear and ultimate ancient gear golem can special summon ancient gear golem from the deck and hand, or graveyard, respectively, but they require much more cost.
Yes. Since you can't special summon, you can't even begin to initiate any kind of special summon. That means assuming a special summon card has a cost of tributing/banishing one monster, you could not use Kristya as that cost. Even if the summon does not use the chain, it is still not possible to tribute/banish Kristya. So the opponent could not tribute your Kristya for his Lava Golem.