Sadly, that is just the way RUST V2 plays out. It's brutal for new players but eventually, you should get a hang of it if you keep playing. Griefing is allowed, however, excessive griefing is not. If he's ONLY coming to your base just to spam place hundreds of blocks, then we may temporarily ban him, otherwise we cannot do anything as griefing is just a part of the game.
A few suggestions for your problem:
- The alt in your base can easily be kicked out by claiming the land. When you place a Faction block to claim a piece of land, people who are logged out inside your base within the claim (and do not belong to your faction) get teleported to the top of the base.
- If you're not already doing this, you should keep your priority chests in your floor,
Like this. That way you don't have to worry too much about your upper walls and you can focus more on the lower layers of the base (namely the 2-3 blocks high layers that protect your chests).
- I do not know how your base is set up, but I would suggest working on adding more layers first instead of trying to upgrade pre-existing layers. When you feel comfortable with your base, use a hammer to slowly upgrade your base (Hammers have different toggle modes that make upgrading easier).
- Finally, if you've got the time and patience, I would actually suggest that you try to do the same to him. It's not against the rules and if it's annoying you, then it'll most likely annoy him too and he might stop.
Once you get more familiar with the game, you'll be able to come up with other creative methods to prevent situations like this one.
This doesn't really belong to Reports. Moved to Questions & Support