Alesha, Who Smiles at Death | Crystalline Crawler | Aggravated Assault (and two other cards)

Cards

All permanents on the battlefield (
Alesha and
Crystalline Crawler without summoning sickness and
Arcbound Overseer with six or more +1/+1 counters on it).

Activate
Crystalline Crawler's second ability by tapping it, putting a +1/+1 counter on it.
Activate
Woe Strider by sacrificing
Arcbound Overseer.
When
Arcbound Overseer dies, it triggers, putting its +1/+1 counters on
Crystalline Crawler.
Resolve the
Woe Strider ability.
Activate
Crystalline Crawler's first ability five times by removing five +1/+1 counters from it, adding ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Activate
Aggravated Assault by paying ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) , causing you to untap all creatures you control and to get an additional combat and main phase after this one.
Declare
Alesha as an attacker, triggering its ability, targeting
Arcbound Overseer.
Activate
Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding ({WB} magic symbol) ({WB} magic symbol) .
Resolve the
Alesha trigger, causing you to pay ({WB} magic symbol) ({WB} magic symbol) to return
Arcbound Overseer from your graveyard to the battlefield tapped and attacking with six +1/+1 counters on it due to its modular ability.
Repeat.

This combo has been estimated to be Exhibition (Bracket 1+).