When the Water meets the Fire in the empty cavity of Ingwaz, it evaporates into clouds of the Air.
You may feel these clouds as a pain in your chest when something hits your ego.
You can also feel it as smoke or exhaust in your chest when your ego inflates disproportionately.

The rune name Algiz is considered to have two main alternative meanings: "Elk", "Elk-sedge", or "Protection". And they all make sense.

Anglo-Saxon rune poem tells about "elk-sedge":

The Elk-sedge usually lives in the fen,
growing in the water. It wounds severely,
staining with blood any man
who makes a grab at it.

There is an idea of killing/dissolving the ego in various spiritual traditions and teachings, but it's wrong to understand it in a destructive "amputational" way.

If there is an ego, then there is some purpose for it. Balancing, centering the ego against your essence, learning always to keep this equilibrium, and never falling into self-aggrandizement or self-deprecation - that's the way for a tightrope walker to the other side. If you cut the rope, you aren't getting anywhere.
Don't fight ego, use your Faith to transform it into a clear soul.

The Algiz rune does exactly that:

• Collect raw heavy dark and opaque clouds to the very center. You can associate this step with exhalation and descending focus of your attention from the breast down to the center part around the solar plexus, so you pump it into the center.
• Hold your breath, tune into the vertical of simultaneity, and let them transmute by extra pressure from above and heat from below.
• Breathe it back from the center into the upper level of Air, your breast, but you will now feel its clean light blue sky, not leaden clouds.

To help yourself preserve even more attention, use a gesture of open palms with wrists placed close to each other, and fingers pointed upward and outside, so the left hand will receive Air from the top left area and send it down to the solar plexus, and the right hand will direct it from the center to the top-right area.

From a geometrical perspective, it's interesting to compare Algiz with Ehwaz. It's the same transition from the Air level to Emptiness and back to Air. But in Ehwaz, the focus is set on the change, on states before and after the transition as indicated by the left and right verticals. And in Algiz, we have a single vertical going right through the center, and we care more about the change as a process.

We were comparing the Ehwaz rune with Hagalaz - they both have two verticals and start at the Air level. And the Hagalaz rune is followed by Naudiz - same transition from Air to Earth, but with a single central vertical instead of two. So we see the same pattern repeats here - after Ehwaz with two verticals, we see the same Air-Emptiness-Air transition of Algiz but with a single central vertical instead.

One can think, why does the change even happen, and how is it possible to change anything? Is the world imperfect, so we should change something to fix it? Or if it is perfect, then any change would cause deviation from the perfection?

The Algiz rune explains that change is the heart of perfection. Take any crooked branch or shard of rock or even a piece of trash left by humans - every single snapshot of reality is perfect, because it has no way to be imperfect. After all, perfection is a full alignment with Order, and natural Order is inevitable. So when something changes, it changes in full alignment with the Order as well. And both states before and after the change are perfect.

We, humans, invented our local version of the Order, adapted to our needs and desires. And often suffer from the observation that not everything fits it.

The key is to understand that human order is derived from the universal order, so when we see something imperfect, we just look at it from this narrowed position of purpose, sense, aesthetics, pain, etc. But we also have an option to step back to the original order and see everything as part of existence, including ourselves.

The center of the Philosopher's Stone is the most mysterious place, and it takes a lot to reach an understanding of what's happening there. That's why so many runes describe actions around the center from different angles.

We already know the Ingwaz rune, and we know that the center is a place where raw Fire and Water meet each other in the pocket of Emptiness. When it just happens, there is a lot of steam, smoke, and clouds in the upper part. At the same time, Fire in the lower part also experiences the dramatic process of cooling down, solidification, and loss of brightness. It feels like losing your power.

But you need to believe in yourself at this point, trust the process. There is a fine thread between the divine spark in your very center and the guiding star at the very top. Very thin, straight, and only strong enough to let you pass. At first, you will slide off and fall, again and again. It's OK, just listen for your true self, just trust - and always get back to the center. At first, the baby learns to stay, then it learns to walk. All the way, baby falls many times, but something makes him try again and again.